diff --git a/platform/lang-api/src/com/intellij/lang/parameterInfo/ParameterInfoUtils.java b/platform/lang-api/src/com/intellij/lang/parameterInfo/ParameterInfoUtils.java
index 92b6e2f55c1e..f8ed8d2ad4ed 100644
--- a/platform/lang-api/src/com/intellij/lang/parameterInfo/ParameterInfoUtils.java
+++ b/platform/lang-api/src/com/intellij/lang/parameterInfo/ParameterInfoUtils.java
@@ -17,10 +17,12 @@
 package com.intellij.lang.parameterInfo;
 
 import com.intellij.lang.ASTNode;
+import com.intellij.openapi.util.Conditions;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiWhiteSpace;
+import com.intellij.psi.SyntaxTraverser;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.util.text.CharArrayUtil;
@@ -53,16 +55,21 @@ public class ParameterInfoUtils {
   }
 
   public static int getCurrentParameterIndex(ASTNode argList, int offset, IElementType delimiterType) {
-    int curOffset = argList.getTextRange().getStartOffset();
+    SyntaxTraverser<ASTNode> s = SyntaxTraverser.astTraverser(argList).expandAndSkip(Conditions.is(argList));
+    return getCurrentParameterIndex(s, offset, delimiterType);
+  }
+
+  public static <V> int getCurrentParameterIndex(SyntaxTraverser<V> s, int offset, IElementType delimiterType) {
+    V root = s.getRoot();
+    int curOffset = s.api.rangeOf(root).getStartOffset();
     if (offset < curOffset) return -1;
-    ASTNode[] children = argList.getChildren(null);
     int index = 0;
 
-    for (ASTNode child : children) {
-      curOffset += child.getTextLength();
+    for (V child : s) {
+      curOffset += s.api.rangeOf(child).getLength();
       if (offset < curOffset) break;
 
-      IElementType type = child.getElementType();
+      IElementType type = s.api.typeOf(child);
       if (type == delimiterType) index++;
     }