diff --git a/src/vim9.h b/src/vim9.h
index 10f983c..39d36f9 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -111,7 +111,8 @@
 
     // expression operations
     ISN_CONCAT,
-    ISN_INDEX,	    // [expr] list index
+    ISN_STRINDEX,   // [expr] string index
+    ISN_LISTINDEX,  // [expr] list index
     ISN_SLICE,	    // drop isn_arg.number items from start of list
     ISN_GETITEM,    // push list item, isn_arg.number is the index
     ISN_MEMBER,	    // dict[member]