src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/LocalVariableTypesCalculator.java

@@ -593,11 +593,11 @@
         if(!reachable) {
             return false;
         }
 
         final Expression init = forNode.getInit();
-        if(forNode.isForIn()) {
+        if(forNode.isForIn() || forNode.isForOf()) {
             final JoinPredecessorExpression iterable = forNode.getModify();
             visitExpression(iterable);
             enterTestFirstLoop(forNode, null, init,
                     // If we're iterating over property names, and we can discern from the runtime environment
                     // of the compilation that the object being iterated over must use strings for property