diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
index 47cc4115b7ac..c70bf120bc66 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
@@ -1298,13 +1298,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
     final int idPlain = varPlain.getID();
     final int idNegated = varNegated == null ? -1 : varNegated.getID();
 
-    if(isNull(varPlain) || isNotNull(varPlain)) {
-      DfaVariableState state = myVariableStates.get(varPlain);
-      if (state != null) {
-        setVariableState(varPlain, state.withoutFact(DfaFactType.CAN_BE_NULL));
-      }
-    }
-
     int[] classes = myIdToEqClassesIndices.get(idPlain);
     int[] negatedClasses = myIdToEqClassesIndices.get(idNegated);
     int[] result = ArrayUtil
diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
index 7df042704c05..0f8932dd6ecf 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
@@ -665,6 +665,10 @@ class StateMerger {
 
     @Override
     void removeFromState(@NotNull DfaMemoryStateImpl state) {
+      if(!myPositive && state.isNotNull(myVar) && state.isNull(myArg)) {
+        // merging "x == null" and "x != null" should be possible with marking "x" as nullable
+        state.forceVariableFact(myVar, CAN_BE_NULL, true);
+      }
       state.removeEquivalenceRelations(myVar);
     }
   }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/NullabilityBasics.java b/java/java-tests/testData/inspection/dataFlow/fixture/NullabilityBasics.java
new file mode 100644
index 000000000000..25dbaf2f37c1
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/NullabilityBasics.java
@@ -0,0 +1,31 @@
+import org.jetbrains.annotations.*;
+
+class NullabilityBasics {
+
+  void test2() {
+    String x = getNullable();
+    if (x == null) {
+      System.out.println("x is null!");
+    }
+    if (isEmpty(x) && Math.random() > 0.5) {
+      return;
+    }
+    System.out.println(x.<warning descr="Method invocation 'trim' may produce 'java.lang.NullPointerException'">trim</warning>());
+  }
+
+  @Nullable String getNullable() {
+    return Math.random() > 0.5 ? null : "";
+  }
+
+  @Contract(value = "null -> true",pure = true)
+  static boolean isEmpty(@Nullable String s) {
+    return s == null || s.isEmpty();
+  }
+
+  void test(String x) {
+    if (x == null) {
+      System.out.println("x is null!");
+    }
+    System.out.println(x.<warning descr="Method invocation 'trim' may produce 'java.lang.NullPointerException'">trim</warning>());
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
index 76cf4cd7774b..bcd2171cecb1 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -582,4 +582,5 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testPrimitiveNull() { doTest(); }
   public void testLessThanRelations() { doTest(); }
   public void testAdvancedArrayAccess() { doTest(); }
+  public void testNullabilityBasics() { doTest(); }
 }