diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
index 70438a15047..aa20759f5c2 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
@@ -366,13 +366,16 @@ internal class DelegatingDataFlowInfo private constructor(
                 updatedNullabilityInfo.entries.fold(
                     parent?.completeNullabilityInfo ?: EMPTY_NULLABILITY_INFO
                 ) { result, (dataFlowValue, nullability) ->
-                    result.put(dataFlowValue, nullability)
+                    if (dataFlowValue.immanentNullability != nullability)
+                        result.put(dataFlowValue, nullability)
+                    else
+                        result.remove(dataFlowValue)
                 }
 
             var resultingTypeInfo = parent?.completeTypeInfo ?: EMPTY_TYPE_INFO
 
             valueToClearPreviousTypeInfo?.let {
-                resultingTypeInfo = resultingTypeInfo.put(it, ImmutableLinkedHashSet.empty())
+                resultingTypeInfo = resultingTypeInfo.remove(it)
             }
 
             for ((value, types) in updatedTypeInfo) {