diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
index 6b65e62b2967..4c439778edae 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
@@ -93,6 +93,12 @@ public class DirectoryIndexImpl extends DirectoryIndex {
       @Override
       public void dispose() {
         myDisposed = true;
+        myState.multiDirPackages.clear();
+        myState.myDirToInfoMap.clear();
+        myState.myDirToPackageName.clear();
+        myState.myExcludeRootsMap.clear();
+        myState.myPackageNameToDirsMap.clear();
+        myState.myProjectExcludeRoots.clear();
       }
     });
   }