diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CamelHumpMatcher.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CamelHumpMatcher.java
index 9b59c4a6ece0..790ad4a886a4 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CamelHumpMatcher.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CamelHumpMatcher.java
@@ -87,6 +87,10 @@ public class CamelHumpMatcher extends PrefixMatcher {
   @Override
   @NotNull
   public PrefixMatcher cloneWithPrefix(@NotNull final String prefix) {
+    if (prefix.equals(myPrefix)) {
+      return this;
+    }
+    
     return new CamelHumpMatcher(prefix, myCaseSensitive);
   }
 
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CompletionServiceImpl.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CompletionServiceImpl.java
index 8cc3b5f3004e..944eb1786047 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CompletionServiceImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/impl/CompletionServiceImpl.java
@@ -143,6 +143,10 @@ public final class CompletionServiceImpl extends CompletionService {
     @Override
     @NotNull
     public CompletionResultSet withPrefixMatcher(@NotNull final PrefixMatcher matcher) {
+      if (matcher.equals(getPrefixMatcher())) {
+        return this;
+      }
+      
       return new CompletionResultSetImpl(getConsumer(), myLengthOfTextBeforePosition, matcher, myContributor, myParameters, mySorter, this);
     }
 
@@ -160,7 +164,7 @@ public final class CompletionServiceImpl extends CompletionService {
     @Override
     @NotNull
     public CompletionResultSet withPrefixMatcher(@NotNull final String prefix) {
-      return withPrefixMatcher(new CamelHumpMatcher(prefix));
+      return withPrefixMatcher(getPrefixMatcher().cloneWithPrefix(prefix));
     }
 
     @NotNull