diff --git a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/commands/semicolon/SmartSemicolonHandler.java b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/commands/semicolon/SmartSemicolonHandler.java
index da489b5..f3d607a 100644
--- a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/commands/semicolon/SmartSemicolonHandler.java
+++ b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/commands/semicolon/SmartSemicolonHandler.java
@@ -41,6 +41,7 @@
 import com.google.eclipse.protobuf.model.util.Protobufs;
 import com.google.eclipse.protobuf.model.util.Resources;
 import com.google.eclipse.protobuf.protobuf.FieldOption;
+import com.google.eclipse.protobuf.protobuf.IndexedElement;
 import com.google.eclipse.protobuf.protobuf.Literal;
 import com.google.eclipse.protobuf.protobuf.MessageField;
 import com.google.eclipse.protobuf.protobuf.Protobuf;
@@ -119,7 +120,7 @@
             }
             if (model instanceof MessageField) {
               MessageField field = (MessageField) model;
-              if (shouldCalculateIndex(field, MESSAGE_FIELD__INDEX)) {
+              if (shouldCalculateIndex(field)) {
                 long index = indexedElements.calculateNewIndexFor(field);
                 field.setIndex(index);
                 updateIndexInCommentOfParent(field, index, document);
@@ -142,6 +143,10 @@
     INode node = nodes.firstNodeForFeature(target, indexAttribute);
     return node == null || isEmpty(node.getText());
   }
+  
+  private boolean shouldCalculateIndex(IndexedElement target) {
+    return indexedElements.indexOf(target) <= 0;
+  }
 
   private EObject modelFrom(ContentAssistContext c) {
     EObject current = c.getCurrentModel();