diff --git a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
index 6ba997f9df6b..9f48727a3d66 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
@@ -524,7 +524,6 @@ public class SwitchBlockHighlightingModel {
     void checkSwitchLabelValues(@NotNull HighlightInfoHolder holder) {
       PsiCodeBlock body = myBlock.getBody();
       if (body == null) return;
-      boolean java20plus = PsiUtil.getLanguageLevel(holder.getProject()).isAtLeast(LanguageLevel.JDK_20_PREVIEW);
       MultiMap<Object, PsiElement> elementsToCheckDuplicates = new MultiMap<>();
       List<List<PsiSwitchLabelStatementBase>> elementsToCheckFallThroughLegality = new SmartList<>();
       List<PsiElement> elementsToCheckDominance = new ArrayList<>();
@@ -558,14 +557,9 @@ public class SwitchBlockHighlightingModel {
       checkDuplicates(elementsToCheckDuplicates, holder);
       if (holder.hasErrorResults()) return;
 
-      if (java20plus) {
-        HashSet<PsiElement> alreadyFallThroughElements = new HashSet<>();
-        checkFallThroughFromToPatternJava20(elementsToCheckFallThroughLegality, holder, alreadyFallThroughElements);
-        checkFallThroughInSwitchLabels(elementsToCheckFallThroughLegality, holder, alreadyFallThroughElements);
-      }
-      else {
-        checkFallThroughFromToPattern(elementsToCheckFallThroughLegality, holder);
-      }
+      HashSet<PsiElement> alreadyFallThroughElements = new HashSet<>();
+      checkFallThroughFromPatternWithSeveralLabels(elementsToCheckFallThroughLegality, holder, alreadyFallThroughElements);
+      checkFallThroughToPatternPrecedingCompleteNormally(elementsToCheckFallThroughLegality, holder, alreadyFallThroughElements);
       if (holder.hasErrorResults()) return;
 
       checkDominance(elementsToCheckDominance, holder);
@@ -775,74 +769,9 @@ public class SwitchBlockHighlightingModel {
       return info;
     }
 
-    /**
-     * 14.11.1 Switch Blocks
-     * <ul>
-     * To ensure safe initialization of pattern variables fall through rules in common provide the restrictions
-     *  of using different type of case label switchLabel:
-     * <li>patterns with patterns</li>
-     * <li>patterns with constants</li>
-     * <li>patterns with default</li>
-     * </ul>
-     */
-    private static void checkFallThroughFromToPattern(@NotNull List<? extends List<PsiSwitchLabelStatementBase>> switchBlockGroup,
-                                                      @NotNull HighlightInfoHolder holder) {
-      if (switchBlockGroup.isEmpty()) return;
-      Set<PsiElement> alreadyFallThroughElements = new HashSet<>();
-      for (var switchLabel : switchBlockGroup) {
-        boolean existPattern = false;
-        boolean existsTypeTestPattern = false;
-        boolean existsConst = false;
-        boolean existsNull = false;
-        boolean existsDefault = false;
-        for (PsiSwitchLabelStatementBase switchLabelElement : switchLabel) {
-          if (switchLabelElement.isDefaultCase()) {
-            if (existPattern) {
-              PsiElement defaultKeyword = switchLabelElement.getFirstChild();
-              addIllegalFallThroughError(defaultKeyword, "switch.illegal.fall.through.from", holder, alreadyFallThroughElements);
-            }
-            existsDefault = true;
-            continue;
-          }
-          PsiCaseLabelElementList labelElementList = switchLabelElement.getCaseLabelElementList();
-          if (labelElementList == null) continue;
-          for (PsiCaseLabelElement currentElement : labelElementList.getElements()) {
-            if (currentElement instanceof PsiPattern || currentElement instanceof PsiPatternGuard) {
-              if (currentElement instanceof PsiTypeTestPattern) {
-                existsTypeTestPattern = true;
-              }
-              if (existPattern || existsConst || (existsNull && !existsTypeTestPattern) || existsDefault) {
-                addIllegalFallThroughError(currentElement, "switch.illegal.fall.through.to", holder, alreadyFallThroughElements);
-              }
-              existPattern = true;
-            }
-            else if (isNullType(currentElement)) {
-              if (existPattern && !existsTypeTestPattern) {
-                addIllegalFallThroughError(currentElement, "switch.illegal.fall.through.from", holder, alreadyFallThroughElements);
-              }
-              existsNull = true;
-            }
-            else if (isConstantLabelElement(currentElement)) {
-              if (existPattern) {
-                addIllegalFallThroughError(currentElement, "switch.illegal.fall.through.from", holder, alreadyFallThroughElements);
-              }
-              existsConst = true;
-            }
-            else if (currentElement instanceof PsiDefaultCaseLabelElement) {
-              if (existPattern) {
-                addIllegalFallThroughError(currentElement, "switch.illegal.fall.through.from", holder, alreadyFallThroughElements);
-              }
-              existsDefault = true;
-            }
-          }
-        }
-      }
-      checkFallThroughInSwitchLabels(switchBlockGroup, holder, alreadyFallThroughElements);
-    }
-
-    private static void checkFallThroughFromToPatternJava20(@NotNull List<List<PsiSwitchLabelStatementBase>> switchBlockGroup,
-                                                            @NotNull HighlightInfoHolder holder,
-                                                            @NotNull Set<PsiElement> alreadyFallThroughElements) {
+    private static void checkFallThroughFromPatternWithSeveralLabels(@NotNull List<List<PsiSwitchLabelStatementBase>> switchBlockGroup,
+                                                                     @NotNull HighlightInfoHolder holder,
+                                                                     @NotNull Set<PsiElement> alreadyFallThroughElements) {
       if (switchBlockGroup.isEmpty()) return;
       for (var switchLabel : switchBlockGroup) {
         for (PsiSwitchLabelStatementBase switchLabelElement : switchLabel) {
@@ -938,9 +867,9 @@ public class SwitchBlockHighlightingModel {
       holder.add(info.create());
     }
 
-    private static void checkFallThroughInSwitchLabels(@NotNull List<? extends List<? extends PsiSwitchLabelStatementBase>> switchBlockGroup,
-                                                       @NotNull HighlightInfoHolder results,
-                                                       @NotNull Set<PsiElement> alreadyFallThroughElements) {
+    private static void checkFallThroughToPatternPrecedingCompleteNormally(@NotNull List<? extends List<? extends PsiSwitchLabelStatementBase>> switchBlockGroup,
+                                                                           @NotNull HighlightInfoHolder results,
+                                                                           @NotNull Set<PsiElement> alreadyFallThroughElements) {
       for (int i = 1; i < switchBlockGroup.size(); i++) {
         List<? extends PsiSwitchLabelStatementBase> switchLabels = switchBlockGroup.get(i);
         PsiSwitchLabelStatementBase firstSwitchLabelInGroup = switchLabels.get(0);
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/EffectivelyFinalWhen.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/EffectivelyFinalWhen.java
index 19e4d9b81692..e08eeef2520c 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/EffectivelyFinalWhen.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/EffectivelyFinalWhen.java
@@ -44,7 +44,7 @@ class Test {
     switch (o) {
       case Integer i when (switch (o) {
         case Integer ii when ii != mode -> 2;
-        case default -> 1;
+        default -> 1;
       }) == mode -> System.out.println();
       default -> {}
     }
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/FallthroughPatternMatchingSwitch.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/FallthroughPatternMatchingSwitch.java
index b478d5139600..e5c9fa93ba7e 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/FallthroughPatternMatchingSwitch.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/FallthroughPatternMatchingSwitch.java
@@ -2,9 +2,9 @@
 class Main {
   void ff(Object o) {
     switch (o) {
-      case String s:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">String s</error>:
       case null:
-      case <error descr="Illegal fall-through to a pattern">Integer i</error>:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>:
         System.out.println(i + 1);
         break;
       case Long l:
@@ -29,7 +29,7 @@ class Main {
   void g(Object o) {
     switch (o) {
       case null:
-      case Integer i:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>:
         System.out.println(i + 1);
       default:
         throw new IllegalStateException("Unexpected value: " + o);
@@ -88,8 +88,8 @@ class Main {
 
   void m(Object o) {
     switch (o) {
-      case String s:
-      case <error descr="Illegal fall-through to a pattern">Integer i</error>:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">String s</error>:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>:
         System.out.println(i + 1);
       default:
         throw new IllegalStateException("Unexpected value: " + o);
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/IllegalFallthroughIn21Java.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/IllegalFallthroughIn21Java.java
new file mode 100644
index 000000000000..46ebeaf3a140
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/IllegalFallthroughIn21Java.java
@@ -0,0 +1,190 @@
+class IllegalFallthroughIn21Java {
+
+
+  public static void test() {
+    Object o = "Hello";
+    switch (o) {
+      case String s:
+        System.out.println();
+      case <error descr="Illegal fall-through to a pattern">Integer i</error>: 
+        System.out.println();
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+
+    }
+  }
+
+  public static void test0() {
+    Object o = "Hello";
+    switch (o) {
+      case null:
+        System.out.println();
+      case <error descr="Illegal fall-through to a pattern">Integer i</error>: 
+        System.out.println();
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+
+    }
+  }
+
+  public static void test2() {
+    Object o = "Hello";
+    switch (o) {
+      case String s:
+        System.out.println();
+        throw new UnsupportedOperationException();
+      case Integer i:
+        System.out.println();
+        break;
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+    }
+  }
+
+  public static void test3() {
+    String o = "Hello";
+    switch (o) {
+      case String s when s.length() == 1:
+        System.out.println();
+      case "1":
+        System.out.println();
+        break;
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+    }
+  }
+
+  public static void test4() {
+    String o = "Hello";
+    switch (o) {
+      case String s when s.length() == 1:
+        System.out.println();
+      case "1":
+        System.out.println(<error descr="Cannot resolve symbol 's'">s</error>); 
+        break;
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+    }
+  }
+
+  public static void test5() {
+    String o = "Hello";
+    switch (o) {
+      case String s when s.length() == 1:
+        System.out.println();
+      case null:
+        System.out.println();
+        break;
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+    }
+  }
+
+  public static void test6() {
+    String o = "Hello";
+    switch (o) {
+      case String s when s.length() == 1:
+        System.out.println();
+      case null:
+        System.out.println(<error descr="Cannot resolve symbol 's'">s</error>); 
+        break;
+      default:
+        throw new IllegalStateException("Unexpected value: " + o);
+    }
+  }
+
+  public static void test7() {
+    Object obj = "Hello";
+    switch (obj) {
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">String s</error>: 
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>: 
+        System.out.println();
+    }
+  }
+
+  public static void test8() {
+    Object obj = "Hello";
+    switch (obj) {
+      case null:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>: 
+        System.out.println();
+    }
+  }
+
+  public static void test9() {
+    String obj = "Hello";
+    switch (obj) {
+      case "a":
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">String i when i.length() == 1</error>: 
+        System.out.println();
+    }
+  }
+
+  public static void test10() {
+    Object obj = "Hello";
+    switch (obj) {
+      case null:
+      case <error descr="Multiple switch labels are permitted for a switch labeled statement group only if none of them declare any pattern variables">Integer i</error>: 
+        System.out.println();
+    }
+  }
+
+  public static void test11() {
+    record R1(){}
+    record R2(){}
+    Object obj = "Hello";
+    switch (obj) {
+      case String s:
+        System.out.println(s);
+      case R1():
+        System.out.println();
+        break;
+      default:
+    }
+
+  }
+
+  public static void test12() {
+    record R1(){}
+    record R2(){}
+    Object obj = "Hello";
+    switch (obj) {
+      case String s:
+        System.out.println(s);
+      case R1():
+        System.out.println(<error descr="Cannot resolve symbol 's'">s</error>); 
+        break;
+      default:
+    }
+
+  }
+
+  public static void test13() {
+    record R1(){}
+    record R2(){}
+    Object obj = "Hello";
+    switch (obj) {
+      case R1():
+      case R2():
+        System.out.println();
+        break;
+      default:
+    }
+
+  }
+
+  public static void test14() {
+    record R1(){}
+    record R2(){}
+    Object obj = null;
+    switch (obj) {
+      case null:
+      case R1():
+      case R2():
+        System.out.println();
+        break;
+      default:
+    }
+
+  }
+}
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/Reachability.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/Reachability.java
index b93d58c7f3f6..897d5c94c03f 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/Reachability.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/Reachability.java
@@ -1,7 +1,7 @@
 import java.util.*;
 
 class Test {
-  void testEnumRechable(Day d) {
+  void testEnumRechable1(Day d) {
     switch (d) {
       case MONDAY, TUESDAY:
         throw new IllegalArgumentException();
@@ -11,14 +11,6 @@ class Test {
     System.out.println();
   }
 
-  void testEnumUncreachable1(Day d) {
-    switch (d) {
-      case MONDAY, TUESDAY, default:
-        throw new IllegalArgumentException();
-    }
-    <error descr="Unreachable statement">System.out.println();</error>
-  }
-
   void testEnumUnreachable2(Day d) {
     switch (d) {
       case Day dd when true:
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExprHasResult.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExprHasResult.java
index ae8b5e0af22c..98d42921a745 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExprHasResult.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExprHasResult.java
@@ -17,7 +17,7 @@ class Test {
     return switch (i) {
       case Integer ii -> {
         switch (i) {
-          case default -> {
+          default -> {
             yield "fsdfs";
           }
         }
@@ -39,12 +39,12 @@ class Test {
 
   String nestedPattern(Object o) {
     return switch (o) {
-      <error descr="Switch expression rule should produce result in all execution paths">case</error> default -> {
+       <error descr="Switch expression rule should produce result in all execution paths">default</error> -> {
         switch (o) {
           case Integer i -> {
             System.out.println(); // completes normally
           }
-          case default -> {
+          default -> {
             yield "fsdfsd";
           }
         }
@@ -56,7 +56,7 @@ class Test {
 
   String switchNestingExpressionStatement(Object o1, Object o2) {
     return switch (o1) {
-      case default -> {
+      default -> {
         switch (o2) {
           case String s2 -> {
             yield "string, string";
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/BoxedTypeNullability.java b/java/java-tests/testData/inspection/dataFlow/fixture/BoxedTypeNullability.java
index 8db0db51e5f7..9acb0be3e55f 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/BoxedTypeNullability.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/BoxedTypeNullability.java
@@ -7,7 +7,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -16,7 +16,7 @@ class Test {
     switch (<warning descr="Unboxing of 'i' may produce 'NullPointerException'">i</warning>) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -28,7 +28,7 @@ class Test {
         break;
       case <warning descr="Switch label 'null' is the only reachable in the whole switch">null</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -40,7 +40,7 @@ class Test {
         break;
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -52,7 +52,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -62,7 +62,7 @@ class Test {
     switch (<warning descr="Unboxing of 'i' may produce 'NullPointerException'">i</warning>) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -72,7 +72,7 @@ class Test {
     switch (i) {
       case <warning descr="Switch label '1' is the only reachable in the whole switch">1</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -83,7 +83,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -92,7 +92,7 @@ class Test {
     switch (i) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -104,7 +104,7 @@ class Test {
         break;
       case <warning descr="Switch label 'null' is the only reachable in the whole switch">null</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -116,7 +116,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -126,7 +126,7 @@ class Test {
     switch (<warning descr="Unboxing of 'i' may produce 'NullPointerException'">i</warning>) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -136,7 +136,7 @@ class Test {
     switch (i) {
       case <warning descr="Switch label '1' is the only reachable in the whole switch">1</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -147,7 +147,7 @@ class Test {
         break;
       case <warning descr="Switch label 'null' is unreachable">null</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -156,7 +156,7 @@ class Test {
     switch (i) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -168,7 +168,7 @@ class Test {
         break;
       case <warning descr="Switch label 'null' is the only reachable in the whole switch">null</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -180,7 +180,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -190,7 +190,7 @@ class Test {
     switch (<warning descr="Unboxing of 'i' may produce 'NullPointerException'">i</warning>) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -200,7 +200,7 @@ class Test {
     switch (i) {
       case <warning descr="Switch label '1' is the only reachable in the whole switch">1</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -211,7 +211,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -220,7 +220,7 @@ class Test {
     switch (<warning descr="Unboxing of 'createNullValue()' may produce 'NullPointerException'">createNullValue()</warning>) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -231,7 +231,7 @@ class Test {
         break;
       case null:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -240,7 +240,7 @@ class Test {
     switch (createValue()) {
       case 1:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -251,7 +251,7 @@ class Test {
         break;
       case <warning descr="Switch label 'null' is unreachable">null</warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/ParameterNullabilityFromSwitch.java b/java/java-tests/testData/inspection/dataFlow/fixture/ParameterNullabilityFromSwitch.java
index e232c5abac07..8e6be7b00c12 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/ParameterNullabilityFromSwitch.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/ParameterNullabilityFromSwitch.java
@@ -12,7 +12,7 @@ class Test {
   static void notNullable(String s) {
     switch (s) {
       case "xyz" -> System.out.println("xyz");
-      case default -> System.out.println("else");
+      default -> System.out.println("else");
     }
   }
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/Patterns.java b/java/java-tests/testData/inspection/dataFlow/fixture/Patterns.java
index b382835bc694..72a71516d698 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/Patterns.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/Patterns.java
@@ -15,7 +15,7 @@ class Test {
         a = -1;
         break;
       }
-      case default: {
+      default: {
         a = 2;
         break;
       }
@@ -35,7 +35,7 @@ class Test {
         a = 1;
         break;
       }
-      case default: {
+      default: {
         a = 2;
         break;
       }
@@ -50,7 +50,7 @@ class Test {
     return switch(FSD) {
       case <warning descr="Switch label 'String s when s.length() <= 3 && (s.length() > 1 || s.length() > 10)' is the only reachable in the whole switch">String s when <warning descr="Condition 's.length() <= 3 && (s.length() > 1 || s.length() > 10)' is always 'true'"><warning descr="Condition 's.length() <= 3' is always 'true'">s.length() <= 3</warning> && (<warning descr="Condition 's.length() > 1 || s.length() > 10' is always 'true' when reached"><warning descr="Condition 's.length() > 1' is always 'true' when reached">s.length() > 1</warning> || s.length() > 10</warning>)</warning></warning> -> 1;
       case String s when Math.random() > 0.5 -> 2;
-      case default -> 3;
+      default -> 3;
     };
   }
 
@@ -66,7 +66,7 @@ class Test {
     switch (FSD) {
       case <warning descr="Switch label 'String s when s.length() > 2 && s.length() < 3' is unreachable">String s when <warning descr="Condition 's.length() > 2 && s.length() < 3' is always 'false'"><warning descr="Condition 's.length() > 2' is always 'true'">s.length() > 2</warning> && <warning descr="Condition 's.length() < 3' is always 'false' when reached">s.length() < 3</warning></warning></warning> -> System.out.println(1);
       case <warning descr="Switch label 'String s when s.isEmpty()' is unreachable">String s when <warning descr="Result of 's.isEmpty()' is always 'false'">s.isEmpty()</warning></warning> -> <error descr="Not a statement">2;</error>
-      case default -> System.out.println(3);
+      default -> System.out.println(3);
     };
   }
 
@@ -81,7 +81,7 @@ class Test {
     String s = "abc";
     switch (s) {
       case <error descr="'switch' has both an unconditional pattern and a default label">Object o</error> -> System.out.println("total");
-      case <error descr="'switch' has both an unconditional pattern and a default label">default</error> -> System.out.println("default");
+      <error descr="'switch' has both an unconditional pattern and a default label">default</error> -> System.out.println("default");
     }
   }
 
@@ -90,7 +90,7 @@ class Test {
     switch (s) {
       case <warning descr="Switch label '\"\"' is unreachable">""</warning> -> System.out.println("abc");
       case <error descr="'switch' has both an unconditional pattern and a default label">Object o</error> -> System.out.println("total");
-      case <error descr="'switch' has both an unconditional pattern and a default label">default</error> -> System.out.println("default");
+      <error descr="'switch' has both an unconditional pattern and a default label">default</error> -> System.out.println("default");
     }
   }
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/PatternsNullability.java b/java/java-tests/testData/inspection/dataFlow/fixture/PatternsNullability.java
index fc504bb00f55..a261e12fc05f 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/PatternsNullability.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/PatternsNullability.java
@@ -97,7 +97,7 @@ class Test {
         break;
       case <warning descr="Switch label 'Object o when !new ArrayList<String>().isEmpty()' is unreachable">Object o when <warning descr="Condition '!new ArrayList<String>().isEmpty()' is always 'false'">!new ArrayList<String>().isEmpty()</warning></warning>:
         break;
-      case default:
+      default:
         break;
     }
   }
@@ -205,7 +205,7 @@ class Test {
     return switch (<warning descr="Unboxing of 'createNullValue()' may produce 'NullPointerException'">createNullValue()</warning>) {
       case 1 -> 1;
       case Object o when Math.random() > 0.5 -> 2;
-      case default -> 3;
+      default -> 3;
     };
   }
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElements.java b/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElements.java
index 1a5079b49197..7fb6a77c939d 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElements.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElements.java
@@ -29,7 +29,7 @@ public class DuplicateLabels {
         break;
       case <error descr="Label is dominated by a preceding case label 'String ss when true'">String ss</error>:
         break;
-      case default:
+      default:
         break;
     }
   }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElementsJava19.java b/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElementsJava19.java
index e408ef18deb0..91de4a775fc6 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElementsJava19.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/SuspiciousLabelElementsJava19.java
@@ -5,21 +5,21 @@ public class Test {
         break;
       case <error descr="Label is dominated by a preceding case label 'String ss when true'">String ss</error>:
         break;
-      case default:
+      default:
         break;
     }
   }
 
   int testDominatedConstLabel(Integer i, E e) {
     switch (e) {
-      case E d when d == E.A: return 1;
-      case <error descr="Label is dominated by a preceding case label 'E d when d == E.A'">A</error>: return -1;
+      case <warning descr="Switch label 'E d when true' is the only reachable in the whole switch">E d when true</warning>: return 1;
+      case <error descr="Label is dominated by a preceding case label 'E d when true'">A</error>: return -1;
     }
 
     return switch (i) {
-      case Integer ii when ii > 2 -> 1;
-      case <error descr="Label is dominated by a preceding case label 'Integer ii when ii > 2'">2</error> -> 2;
-      case default -> 3;
+      case Integer ii when true -> 1;
+      case <error descr="Label is dominated by a preceding case label 'Integer ii when true'">2</error> -> 2;
+      default -> 3;
     };
   }
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/WhenPatterns.java b/java/java-tests/testData/inspection/dataFlow/fixture/WhenPatterns.java
index 0bd40236ad9c..5d6d115a5e54 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/WhenPatterns.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/WhenPatterns.java
@@ -8,14 +8,14 @@ class Test {
   int test3(String s1) {
     return switch(s1) {
       case String s when s.length() <= 3 && (s.length() > 1 || <warning descr="Condition 's.length() > 10' is always 'false' when reached">s.length() > 10</warning>) -> 1;
-      case default -> 3;
+      default -> 3;
     };
   }
 
   int test4(String s) {
     return switch (s) {
       case String ss when (ss.length() < 3 || ss.length() == 4) -> 1;
-      case default -> 3;
+      default -> 3;
     };
   }
 
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
index 3314af962cfb..b839c0933f48 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
@@ -47,6 +47,9 @@ public class LightPatternsForSwitchHighlightingTest extends LightJavaCodeInsight
   public void testIllegalFallthroughIn20Java() {
     IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_20_PREVIEW, this::doTest);
   }
+  public void testIllegalFallthroughIn21Java() {
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_21, this::doTest);
+  }
 
   public void testUnconditionalDestructuringAndDefaultIn21Java() {
     IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_21, this::doTest);
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
index 2fd9cda0827f..9bc880e5eed8 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
@@ -6,6 +6,7 @@ import com.intellij.testFramework.LightProjectDescriptor;
 import org.jetbrains.annotations.NotNull;
 
 public class DataFlowInspection21Test extends DataFlowInspectionTestCase {
+
   @NotNull
   @Override
   protected LightProjectDescriptor getProjectDescriptor() {
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/afterBeforeCaseDefault.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/afterBeforeCaseDefault.java
index d70d5bd110bc..3ba55e6f98c0 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/afterBeforeCaseDefault.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/afterBeforeCaseDefault.java
@@ -12,7 +12,7 @@ class Main {
         break;
         case ERROR:
             break;
-        case default:
+        default:
         throw new IllegalArgumentException("Unknown Status " + status);
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/beforeBeforeCaseDefault.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/beforeBeforeCaseDefault.java
index df6f367a95e4..1a8dff59a546 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/beforeBeforeCaseDefault.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/controlflow/enumswitch/beforeBeforeCaseDefault.java
@@ -10,7 +10,7 @@ class Main {
         break;
       case INACTIVE:
         break;
-      case default:
+      default:
         throw new IllegalArgumentException("Unknown Status " + status);
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.after.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.after.java
index 8cb27d4bedbb..85dbfd79fa37 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.after.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.after.java
@@ -8,7 +8,7 @@ class Test {
         break;
         case null:
             break;
-        case default:
+        default:
         break;
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.java
index fa28f98edc13..a8963261abb4 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/DefaultExists.java
@@ -6,7 +6,7 @@ class Test {
       case 1:
         System.out.println();
         break;
-      case default:
+      default:
         break;
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.after.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.after.java
index d3b3e24fd082..103376637c3f 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.after.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.after.java
@@ -8,7 +8,7 @@ class Test {
           break;
         case null:
             break;
-        case default:
+        default:
         break;
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.java
index 1735b6d5242f..1d3ac962f859 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/PrevStatementCompletesNormally.java
@@ -5,7 +5,7 @@ class Test {
     switch ((<caret>i)) {
       case 1:
         System.out.println();
-      case default:
+      default:
         break;
     }
   }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.after.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.after.java
index 9a335ea569f4..05dec4caf514 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.after.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.after.java
@@ -6,7 +6,7 @@ class Test {
       case 1 -> System.out.println();
         case null -> {
         }
-        case default -> System.out.println();
+        default -> System.out.println();
     }
   }
 }
\ No newline at end of file
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.java
index 981587d8e8de..c1455ece4ec3 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/RuleWithDefaultExists.java
@@ -4,7 +4,7 @@ class Test {
   void test(@Nullable Integer i) {
     switch ((<caret>i)) {
       case 1 -> System.out.println();
-      case default -> System.out.println();
+      default -> System.out.println();
     }
   }
 }
\ No newline at end of file
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.after.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.after.java
index cc10e4a8a4b5..1a56c082dff3 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.after.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.after.java
@@ -6,7 +6,7 @@ class Test {
         case null -> 0;
         case String s && s.length() <= 3 -> 1;
       case "abc" -> 2;
-      case default -> 3;
+      default -> 3;
     };
   }
 }
\ No newline at end of file
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.java b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.java
index a2575687b15a..c77cadbdd078 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igfixes/dataflow/create_null_branch/UnconditionalPatternNotExist.java
@@ -5,7 +5,7 @@ class Test {
     return switch (<caret>s) {
       case String s && s.length() <= 3 -> 1;
       case "abc" -> 2;
-      case default -> 3;
+      default -> 3;
     };
   }
 }
\ No newline at end of file
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/switch_statement_with_too_few_branches/SwitchStatementWithTooFewBranches.java b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/switch_statement_with_too_few_branches/SwitchStatementWithTooFewBranches.java
index a25eb90f0ec4..15deec9ceb66 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/switch_statement_with_too_few_branches/SwitchStatementWithTooFewBranches.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/switch_statement_with_too_few_branches/SwitchStatementWithTooFewBranches.java
@@ -70,12 +70,12 @@ class SwitchStatementWithTooFewBranches {
     }
 
     <warning descr="'switch' statement has only 'default' case">switch</warning> (o) {
-      case default -> System.out.println();
+      default -> System.out.println();
     }
 
     <warning descr="'switch' statement has too few case labels (1), and should probably be replaced with an 'if' statement">switch</warning> (o) {
       case null -> System.out.println();
-      case default -> System.out.println();
+      default -> System.out.println();
     }
   }
 
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/unnecessary_default/UnnecessaryDefault.java b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/unnecessary_default/UnnecessaryDefault.java
index ba19242f2bed..798915d18a25 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/unnecessary_default/UnnecessaryDefault.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/unnecessary_default/UnnecessaryDefault.java
@@ -162,7 +162,7 @@ public class UnnecessaryDefault{
         switch (e) {
           case foo, bar, baz:
             break;
-          case /**test**/ <warning descr="'default' branch is unnecessary">default</warning> /**test**/:
+          /**test**/ <warning descr="'default' branch is unnecessary">default</warning> /**test**/:
             break;
         }
     }
@@ -182,7 +182,7 @@ public class UnnecessaryDefault{
             break;
           case C2 c2:
             break;
-          case /**test**/ <warning descr="'default' branch is unnecessary">default</warning> /**test**/:
+          /**test**/ <warning descr="'default' branch is unnecessary">default</warning> /**test**/:
             break;
         }
     }
@@ -204,7 +204,7 @@ public class UnnecessaryDefault{
             break;
           case C4 c4:
             break;
-          case default:
+          default:
             break;
         }
     }
diff --git a/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/SwitchStatementWithTooFewBranchesInspectionTest.java b/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/SwitchStatementWithTooFewBranchesInspectionTest.java
index 9d0578cfefb9..e54186100313 100644
--- a/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/SwitchStatementWithTooFewBranchesInspectionTest.java
+++ b/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/SwitchStatementWithTooFewBranchesInspectionTest.java
@@ -22,6 +22,6 @@ public class SwitchStatementWithTooFewBranchesInspectionTest extends LightJavaIn
 
   @Override
   protected @NotNull LightProjectDescriptor getProjectDescriptor() {
-    return JAVA_20;
+    return JAVA_21;
   }
 }
diff --git a/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/UnnecessaryDefaultInspectionTest.java b/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/UnnecessaryDefaultInspectionTest.java
index a63418a80222..2856d65b0ef1 100644
--- a/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/UnnecessaryDefaultInspectionTest.java
+++ b/plugins/InspectionGadgets/testsrc/com/siyeh/ig/controlflow/UnnecessaryDefaultInspectionTest.java
@@ -107,26 +107,6 @@ public class UnnecessaryDefaultInspectionTest extends LightJavaInspectionTestCas
                   "}");
   }
 
-  public void testCaseDefaultWithEnumElements() {
-    doTest("class X {" +
-           "  void x(E e) {" +
-           "    switch (e) {" +
-           "      case A, /*'default' branch is unnecessary*/default/*_*//**/, B:" +
-           "        break;" +
-           "    }" +
-           "  }" +
-           "}");
-    checkQuickFix("Remove 'default' branch",
-                  "class X {" +
-                  "  void x(E e) {" +
-                  "    switch (e) {" +
-                  "      case A, B:" +
-                  "        break;" +
-                  "    }" +
-                  "  }" +
-                  "}");
-  }
-
   public void testCaseDefaultInSealedSwitch() {
     doTest("class X {" +
            "  void x(I i) {" +
@@ -157,34 +137,6 @@ public class UnnecessaryDefaultInspectionTest extends LightJavaInspectionTestCas
                   "}");
   }
 
-  public void testCaseDefaultWithPattern() {
-    doTest("class X {" +
-           "  void x(I i) {" +
-           "    switch (i) {" +
-           "      case /*'default' branch is unnecessary*/default/*_*//**/, <error descr=\"Illegal fall-through to a pattern\">I ii when Math.random() > 0.5</error>:" +
-           "        break;" +
-           "      case C1 c1:" +
-           "        break;" +
-           "      case C2 c2:" +
-           "        break;" +
-           "    }" +
-           "  }" +
-           "}");
-    checkQuickFix("Remove 'default' branch",
-                  "class X {" +
-                  "  void x(I i) {" +
-                  "    switch (i) {" +
-                  "      case I ii when Math.random() > 0.5:" +
-                  "        break;" +
-                  "      case C1 c1:" +
-                  "        break;" +
-                  "      case C2 c2:" +
-                  "        break;" +
-                  "    }" +
-                  "  }" +
-                  "}");
-  }
-
   public void testDefaultInParameterizedSealedHierarchy() {
     doTest("class X {" +
            "  void x(J<Integer> j) {" +