diff --git a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/BasicCompletionSession.kt b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/BasicCompletionSession.kt
index bb79aabfa12..7432656a71e 100644
--- a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/BasicCompletionSession.kt
+++ b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/BasicCompletionSession.kt
@@ -464,8 +464,14 @@ class BasicCompletionSession(
                                         .filterNot { it.original in foundDescriptors }
                                         .onEach { foundDescriptors += it.original }
 
-                                collector.addDescriptorElements(unique.toList(), factory)
-                                collector.addDescriptorElements(uniqueNotImportedExtensions.toList(), factory, notImported = true)
+                                collector.addDescriptorElements(
+                                    unique.toList(), factory,
+                                    prohibitDuplicates = true
+                                )
+                                collector.addDescriptorElements(
+                                    uniqueNotImportedExtensions.toList(), factory,
+                                    notImported = true, prohibitDuplicates = true
+                                )
 
                                 flushToResultSet()
                             }
@@ -796,8 +802,14 @@ class BasicCompletionSession(
 
     private fun addReferenceVariantElements(lookupElementFactory: LookupElementFactory, descriptorKindFilter: DescriptorKindFilter) {
         fun addReferenceVariants(referenceVariants: ReferenceVariants) {
-            collector.addDescriptorElements(referenceVariantsHelper.excludeNonInitializedVariable(referenceVariants.imported, position), lookupElementFactory)
-            collector.addDescriptorElements(referenceVariants.notImportedExtensions, lookupElementFactory, notImported = true)
+            collector.addDescriptorElements(
+                referenceVariantsHelper.excludeNonInitializedVariable(referenceVariants.imported, position),
+                lookupElementFactory, prohibitDuplicates = true
+            )
+            collector.addDescriptorElements(
+                referenceVariants.notImportedExtensions, lookupElementFactory,
+                notImported = true, prohibitDuplicates = true
+            )
         }
 
         val referenceVariantsCollector = referenceVariantsCollector!!
diff --git a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/DslMembersCompletion.kt b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/DslMembersCompletion.kt
index cc0d90aa804..9be7a104ce7 100644
--- a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/DslMembersCompletion.kt
+++ b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/DslMembersCompletion.kt
@@ -64,7 +64,7 @@ class DslMembersCompletion(
             callTypeAndReceiver = callTypeAndReceiver,
             receiverTypes = listOf(nearestReceiver.type)
         ).forEach { descriptor: DeclarationDescriptor ->
-            collector.addDescriptorElements(descriptor, factory, notImported = true, withReceiverCast = false)
+            collector.addDescriptorElements(descriptor, factory, notImported = true, withReceiverCast = false, prohibitDuplicates = true)
         }
 
         collector.flushToResultSet()
diff --git a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt
index 37dd294c56f..9794ee01fa1 100644
--- a/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt
+++ b/idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt
@@ -68,23 +68,26 @@ class LookupElementsCollector(
         postProcessors.add(processor)
     }
 
-    fun addDescriptorElements(descriptors: Iterable<DeclarationDescriptor>,
-                                     lookupElementFactory: AbstractLookupElementFactory,
-                                     notImported: Boolean = false,
-                                     withReceiverCast: Boolean = false
+    fun addDescriptorElements(
+        descriptors: Iterable<DeclarationDescriptor>,
+        lookupElementFactory: AbstractLookupElementFactory,
+        notImported: Boolean = false,
+        withReceiverCast: Boolean = false,
+        prohibitDuplicates: Boolean = false
     ) {
         for (descriptor in descriptors) {
-            addDescriptorElements(descriptor, lookupElementFactory, notImported, withReceiverCast)
+            addDescriptorElements(descriptor, lookupElementFactory, notImported, withReceiverCast, prohibitDuplicates)
         }
     }
 
     fun addDescriptorElements(
-            descriptor: DeclarationDescriptor,
-            lookupElementFactory: AbstractLookupElementFactory,
-            notImported: Boolean = false,
-            withReceiverCast: Boolean = false
+        descriptor: DeclarationDescriptor,
+        lookupElementFactory: AbstractLookupElementFactory,
+        notImported: Boolean = false,
+        withReceiverCast: Boolean = false,
+        prohibitDuplicates: Boolean = false
     ) {
-        if (descriptor is CallableDescriptor && descriptor in processedCallables) return
+        if (prohibitDuplicates && descriptor is CallableDescriptor && descriptor in processedCallables) return
 
         var lookupElements = lookupElementFactory.createStandardLookupElementsForDescriptor(descriptor, useReceiverTypes = true)
 
@@ -94,7 +97,7 @@ class LookupElementsCollector(
 
         addElements(lookupElements, notImported)
 
-        if (descriptor is CallableDescriptor) processedCallables.add(descriptor)
+        if (prohibitDuplicates && descriptor is CallableDescriptor) processedCallables.add(descriptor)
     }
 
     fun addElement(element: LookupElement, notImported: Boolean = false) {