diff --git a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
index bd63ee6f81c9..32aa1c0fdbc7 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
@@ -181,6 +181,7 @@ public class PsiNamesElementSignatureProvider extends AbstractElementSignaturePr
         return null;
       }
       int index = getChildIndex(named, element.getParent(), name, PsiNamedElement.class);
+      if (index < 0) return null;
       StringBuilder bufferToUse = buffer;
       if (bufferToUse == null) {
         bufferToUse = new StringBuilder();