diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
index 0217b819ce3b..be70ba0e4328 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
@@ -31,6 +31,10 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
 
+import static com.intellij.psi.JavaTokenType.*;
+import static com.intellij.psi.JavaTokenType.EQEQ;
+import static com.intellij.psi.JavaTokenType.NE;
+
 /**
  * @author peter
  */
@@ -184,7 +188,7 @@ public class StandardInstructionVisitor extends InstructionVisitor {
     DfaValue dfaExpr = factory.createValue(instruction.getCasted());
     if (dfaExpr != null) {
       DfaTypeValue dfaType = (DfaTypeValue)factory.createTypeValue(instruction.getCastTo(), Nullness.UNKNOWN);
-      DfaRelationValue dfaInstanceof = factory.getRelationFactory().createRelation(dfaExpr, dfaType, JavaTokenType.INSTANCEOF_KEYWORD, false);
+      DfaRelationValue dfaInstanceof = factory.getRelationFactory().createRelation(dfaExpr, dfaType, INSTANCEOF_KEYWORD, false);
       if (dfaInstanceof != null && !memState.applyInstanceofOrNull(dfaInstanceof)) {
         onInstructionProducesCCE(instruction);
       }
@@ -289,7 +293,12 @@ public class StandardInstructionVisitor extends InstructionVisitor {
   protected boolean checkNotNullable(DfaMemoryState state,
                                      DfaValue value, NullabilityProblem problem,
                                      PsiElement anchor) {
-    return state.checkNotNullable(value);
+    boolean notNullable = state.checkNotNullable(value);
+    if (notNullable && problem != NullabilityProblem.passingNullableArgumentToNonAnnotatedParameter) {
+      DfaValueFactory factory = ((DfaMemoryStateImpl)state).getFactory();
+      state.applyCondition(factory.getRelationFactory().createRelation(value, factory.getConstFactory().getNull(), NE, false));
+    }
+    return notNullable;
   }
 
   @Override
@@ -309,7 +318,7 @@ public class StandardInstructionVisitor extends InstructionVisitor {
         return states;
       }
 
-      if (JavaTokenType.PLUS == opSign) {
+      if (PLUS == opSign) {
         memState.push(instruction.getNonNullStringValue(runner.getFactory()));
       }
       else {
@@ -415,12 +424,12 @@ public class StandardInstructionVisitor extends InstructionVisitor {
                                                                 DfaValue dfaRight,
                                                                 DfaValue dfaLeft) {
     final IElementType opSign = instruction.getOperationSign();
-    if (JavaTokenType.EQEQ != opSign && JavaTokenType.NE != opSign ||
+    if (EQEQ != opSign && NE != opSign ||
         !(dfaLeft instanceof DfaConstValue) || !(dfaRight instanceof DfaConstValue)) {
       return null;
     }
 
-    boolean negated = (JavaTokenType.NE == opSign) ^ (DfaMemoryStateImpl.isNaN(dfaLeft) || DfaMemoryStateImpl.isNaN(dfaRight));
+    boolean negated = (NE == opSign) ^ (DfaMemoryStateImpl.isNaN(dfaLeft) || DfaMemoryStateImpl.isNaN(dfaRight));
     if (dfaLeft == dfaRight ^ negated) {
       memState.push(runner.getFactory().getConstFactory().getTrue());
       instruction.setTrueReachable();
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/ComparingToNotNullShouldNotAffectNullity.java b/java/java-tests/testData/inspection/dataFlow/fixture/ComparingToNotNullShouldNotAffectNullity.java
index fed3d1b79015..98c26df45721 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/ComparingToNotNullShouldNotAffectNullity.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/ComparingToNotNullShouldNotAffectNullity.java
@@ -18,6 +18,27 @@ class Bar3 {
       if (first == getObj() || collection.size() > 0) {
         System.out.println(first.hashCode());
       }
+      if (<warning descr="Condition 'first == null' is always 'false'">first == null</warning>) {
+        System.out.println(first.hashCode());
+      }
+    }
+  }
+
+  void foo2(Collection<Object> collection) {
+    if (!collection.isEmpty()) {
+      Object first = collection.iterator().next();
+      if (first != getObj() || collection.size() > 0) {
+        first.hashCode();
+      }
+    }
+  }
+
+  void foo3(Collection<Object> collection) {
+    if (!collection.isEmpty()) {
+      Object first = collection.iterator().next();
+      if (first == getObj() || collection.size() > 2) {
+        System.out.println(first.hashCode());
+      }
       if (first == null) {
         System.out.println(<warning descr="Method invocation 'first.hashCode()' may produce 'java.lang.NullPointerException'">first.hashCode()</warning>);
       }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/NotNullAfterDereference.java b/java/java-tests/testData/inspection/dataFlow/fixture/NotNullAfterDereference.java
new file mode 100644
index 000000000000..5c6dc81fe339
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/NotNullAfterDereference.java
@@ -0,0 +1,9 @@
+class Foo {
+
+  private void someMethod(String someArg) {
+    someArg.getClass();
+    if (<warning descr="Condition 'someArg == null' is always 'false'">someArg == null</warning>) {
+      System.err.println("Wrong argument");
+    }
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
index ddec53269a1c..80b6e028db00 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
@@ -309,6 +309,8 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
 
   public void testUnusedCallDoesNotMakeUnknown() { doTest(); }
   public void testGettersAndPureNoFlushing() { doTest(); }
+  
+  public void testNotNullAfterDereference() { doTest(); }
 
   public void testSameComparisonTwice() { doTest(); }