diff --git a/platform/lang-api/src/com/intellij/psi/ForceableComparable.java b/platform/lang-api/src/com/intellij/psi/ForceableComparable.java
new file mode 100644
index 000000000000..643b1c6debef
--- /dev/null
+++ b/platform/lang-api/src/com/intellij/psi/ForceableComparable.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2000-2011 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi;
+
+/**
+ * @author peter
+ */
+public interface ForceableComparable {
+  void force();
+}
diff --git a/platform/lang-api/src/com/intellij/psi/WeighingComparable.java b/platform/lang-api/src/com/intellij/psi/WeighingComparable.java
index 4fc1aac16d35..69b03fc2bb59 100644
--- a/platform/lang-api/src/com/intellij/psi/WeighingComparable.java
+++ b/platform/lang-api/src/com/intellij/psi/WeighingComparable.java
@@ -22,7 +22,7 @@ import org.jetbrains.annotations.Nullable;
 /**
  * @author peter
 */
-public class WeighingComparable<T,Loc> implements Comparable<WeighingComparable<T,Loc>> {
+public class WeighingComparable<T,Loc> implements Comparable<WeighingComparable<T,Loc>>, ForceableComparable {
   private static final Comparable NULL = new Comparable() {
     public int compareTo(final Object o) {
       throw new UnsupportedOperationException("Method compareTo is not yet implemented in " + getClass().getName());
@@ -45,8 +45,8 @@ public class WeighingComparable<T,Loc> implements Comparable<WeighingComparable<
   public void force() {
     for (int i = 0; i < myComputedWeighs.length; i++) {
       Comparable weight = getWeight(i);
-      if (weight instanceof WeighingComparable) {
-        ((WeighingComparable)weight).force();
+      if (weight instanceof ForceableComparable) {
+        ((ForceableComparable)weight).force();
       }
     }
   }
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/NegatingComparable.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/NegatingComparable.java
index 36f02aa13dd8..b39a4b5f4981 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/NegatingComparable.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/NegatingComparable.java
@@ -15,16 +15,25 @@
  */
 package com.intellij.codeInsight.completion.impl;
 
+import com.intellij.psi.ForceableComparable;
+
 /**
 * @author peter
 */
-public class NegatingComparable<T extends NegatingComparable<T>> implements Comparable<T> {
+public class NegatingComparable<T extends NegatingComparable<T>> implements Comparable<T>, ForceableComparable {
   private final Comparable myWeigh;
 
   public NegatingComparable(Comparable weigh) {
     myWeigh = weigh;
   }
 
+  @Override
+  public void force() {
+    if (myWeigh instanceof ForceableComparable) {
+      ((ForceableComparable)myWeigh).force();
+    }
+  }
+
   @Override
   public int compareTo(T o) {
     final Comparable w1 = myWeigh;
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/CachingComparingClassifier.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/CachingComparingClassifier.java
index 56800dda1ae7..e83ce85c0855 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/CachingComparingClassifier.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/CachingComparingClassifier.java
@@ -15,7 +15,7 @@
  */
 package com.intellij.codeInsight.lookup;
 
-import com.intellij.psi.WeighingComparable;
+import com.intellij.psi.ForceableComparable;
 import gnu.trove.THashMap;
 import gnu.trove.TObjectHashingStrategy;
 import org.jetbrains.annotations.NotNull;
@@ -47,8 +47,8 @@ public class CachingComparingClassifier extends ComparingClassifier<LookupElemen
   @Override
   public void addElement(LookupElement t) {
     Comparable weight = myWeigher.weigh(t);
-    if (weight instanceof WeighingComparable) {
-      ((WeighingComparable)weight).force();
+    if (weight instanceof ForceableComparable) {
+      ((ForceableComparable)weight).force();
     }
     myWeights.put(t, weight);
     super.addElement(t);