diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java b/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java
index 32f3698bc8a..93fbf8f10a3 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java
@@ -33,6 +33,7 @@ import org.jetbrains.jet.lang.resolve.calls.CallMaker;
 import org.jetbrains.jet.lang.resolve.calls.OverloadResolutionResults;
 import org.jetbrains.jet.lang.resolve.calls.OverloadResolutionResultsUtil;
 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
+import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValue;
 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory;
 import org.jetbrains.jet.lang.resolve.constants.*;
 import org.jetbrains.jet.lang.resolve.constants.StringValue;
@@ -784,6 +785,10 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             if (isKnownToBeNotNull(baseExpression, context)) {
                 context.trace.report(UNNECESSARY_NOT_NULL_ASSERTION.on(operationSign, type));
             }
+            else {
+                DataFlowValue value = DataFlowValueFactory.INSTANCE.createDataFlowValue(baseExpression, type, context.trace.getBindingContext());
+                dataFlowInfo = dataFlowInfo.disequate(value, DataFlowValue.NULL);
+            }
             return DataFlowUtils.checkType(TypeUtils.makeNotNullable(type), expression, context, dataFlowInfo);
         }
 
diff --git a/compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/kt2164.jet b/compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/kt2164.jet
new file mode 100644
index 00000000000..79029f1165a
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/kt2164.jet
@@ -0,0 +1,38 @@
+//KT-2164 !! does not propagate nullability information
+package kt2164
+
+fun foo(x: Int): Int = x + 1
+
+fun main(args : Array<String>) {
+    val x: Int? = null
+
+    foo(<!TYPE_MISMATCH!>x<!>)
+
+    if (x != null) {
+        foo(x)
+        foo(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
+        foo(x)
+    }
+
+    foo(<!TYPE_MISMATCH!>x<!>)
+
+    if (x != null) {
+        foo(x)
+        foo(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
+        foo(x)
+    } else {
+        foo(<!TYPE_MISMATCH!>x<!>)
+        foo(x!!)
+        foo(x)
+    }
+
+    foo(x)
+    foo(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
+    foo(x)
+    
+    val y: Int? = null
+    y!!
+    y<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
+    foo(y)
+    foo(y<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
+}