diff --git a/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java b/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
index a7e07136fbc9..1de0393acde6 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
@@ -398,30 +398,7 @@ public class MapReduceIndex<Key, Value, Input> implements UpdatableIndex<Key,Val
     if (data == null) {
       data = content != null ? myIndexer.map(content) : Collections.<Key, Value>emptyMap();
       if (DebugAssertions.EXTRA_SANITY_CHECKS) {
-
-        for(Map.Entry<Key, Value> e: data.entrySet()) {
-          final Value value = e.getValue();
-          if (!(Comparing.equal(value, value) && (value == null || value.hashCode() == value.hashCode()))) {
-            LOG.error("Index %s violates equals / hashCode contract for Value parameter", myIndexId.toString());
-          }
-
-          if (myValueExternalizer != null) {
-            try {
-              final BufferExposingByteArrayOutputStream out = new BufferExposingByteArrayOutputStream();
-              DataOutputStream outputStream = new DataOutputStream(out);
-              myValueExternalizer.save(outputStream, value);
-              outputStream.close();
-              final Value deserializedValue =
-                myValueExternalizer.read(new DataInputStream(new UnsyncByteArrayInputStream(out.getInternalBuffer(), 0, out.size())));
-
-              if (!(Comparing.equal(value, deserializedValue) && (value == null || value.hashCode() == deserializedValue.hashCode()))) {
-                LOG.error("Index %s violates equals / hashCode contract for Value parameter", myIndexId.toString());
-              }
-            } catch (IOException ex) {
-              LOG.error(ex);
-            }
-          }
-        }
+        checkValuesHaveProperEqualsAndHashCode(data);
       }
     }
 
@@ -576,6 +553,32 @@ public class MapReduceIndex<Key, Value, Input> implements UpdatableIndex<Key,Val
     };
   }
 
+  private void checkValuesHaveProperEqualsAndHashCode(Map<Key, Value> data) {
+    for(Map.Entry<Key, Value> e: data.entrySet()) {
+      final Value value = e.getValue();
+      if (!(Comparing.equal(value, value) && (value == null || value.hashCode() == value.hashCode()))) {
+        LOG.error("Index " + myIndexId.toString() + " violates equals / hashCode contract for Value parameter");
+      }
+
+      if (myValueExternalizer != null) {
+        try {
+          final BufferExposingByteArrayOutputStream out = new BufferExposingByteArrayOutputStream();
+          DataOutputStream outputStream = new DataOutputStream(out);
+          myValueExternalizer.save(outputStream, value);
+          outputStream.close();
+          final Value deserializedValue =
+            myValueExternalizer.read(new DataInputStream(new UnsyncByteArrayInputStream(out.getInternalBuffer(), 0, out.size())));
+
+          if (!(Comparing.equal(value, deserializedValue) && (value == null || value.hashCode() == deserializedValue.hashCode()))) {
+            LOG.error("Index " + myIndexId.toString() + " violates equals / hashCode contract for Value parameter");
+          }
+        } catch (IOException ex) {
+          LOG.error(ex);
+        }
+      }
+    }
+  }
+
   private StringBuilder buildDiff(Map<Key, Value> data, Map<Key, Value> contentData) {
     StringBuilder moreInfo = new StringBuilder();
     if (contentData.size() != data.size()) {