diff --git a/idea/src/org/jetbrains/jet/plugin/references/JetSimpleNameReference.java b/idea/src/org/jetbrains/jet/plugin/references/JetSimpleNameReference.java
index 7224322b46ebbdc4da6852521c665b9b4ad72ac6..03fe53b1c8b86d0edae73741e6df92be88021dc9 100644
--- a/idea/src/org/jetbrains/jet/plugin/references/JetSimpleNameReference.java
+++ b/idea/src/org/jetbrains/jet/plugin/references/JetSimpleNameReference.java
@@ -17,12 +17,16 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.calls.inference.*;
+import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintResolutionListener;
+import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystem;
+import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemImpl;
+import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemSolution;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.resolve.scopes.JetScopeUtils;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 import org.jetbrains.jet.lang.types.JetType;
+import org.jetbrains.jet.lang.types.NamespaceType;
 import org.jetbrains.jet.lang.types.Variance;
 import org.jetbrains.jet.plugin.compiler.WholeProjectAnalyzerFacade;
 import org.jetbrains.jet.plugin.completion.handlers.JetFunctionInsertHandler;
@@ -105,6 +109,7 @@ class JetSimpleNameReference extends JetPsiReference {
             @NotNull Iterable<DeclarationDescriptor> descriptors, @NotNull final JetScope scope
     ) {
         final Set<DeclarationDescriptor> descriptorsSet = Sets.newHashSet(descriptors);
+
         descriptorsSet.removeAll(
                 Collections2.filter(JetScopeUtils.getAllExtensions(scope), new Predicate<CallableDescriptor>() {
                     @Override
@@ -121,6 +126,11 @@ class JetSimpleNameReference extends JetPsiReference {
             @NotNull final JetScope externalScope,
             @NotNull final ReceiverDescriptor receiverDescriptor
     ) {
+        // It's impossible to add extension function for namespace
+        if (receiverDescriptor.getType() instanceof NamespaceType) {
+            return descriptors;
+        }
+
         Set<DeclarationDescriptor> descriptorsSet = Sets.newHashSet(descriptors);
 
         descriptorsSet.addAll(Collections2.filter(JetScopeUtils.getAllExtensions(externalScope),
diff --git a/idea/testData/completion/basic/SubpackageInFun.kt b/idea/testData/completion/basic/SubpackageInFun.kt
new file mode 100644
index 0000000000000000000000000000000000000000..52a9b1022e7b511facc13a8979ef47c63a9eb9f4
--- /dev/null
+++ b/idea/testData/completion/basic/SubpackageInFun.kt
@@ -0,0 +1,7 @@
+namespace Test.MyTest
+
+fun test() {
+    Test.<caret>
+}
+
+// EXIST: MyTest
\ No newline at end of file