diff --git a/platform/util/src/com/intellij/util/containers/CollectionFactory.java b/platform/util/src/com/intellij/util/containers/CollectionFactory.java
index 897a40b98810..11f0326cc6fd 100644
--- a/platform/util/src/com/intellij/util/containers/CollectionFactory.java
+++ b/platform/util/src/com/intellij/util/containers/CollectionFactory.java
@@ -20,6 +20,8 @@ import gnu.trove.THashSet;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
+import java.util.Stack;
+import java.util.HashSet;
 
 /**
  * @author peter