diff --git a/benchmark/fib/fib.tra b/benchmark/fib/fib.tra
index e93fc0dd..3ccbadc7 100644
--- a/benchmark/fib/fib.tra
+++ b/benchmark/fib/fib.tra
@@ -6,5 +6,5 @@ sub fib($n) {
     }
 }
 
-say(fib(20));
+say(fib(39));
 
diff --git a/vm.inc b/vm.inc
index 800c5c50..3e98b3ae 100644
--- a/vm.inc
+++ b/vm.inc
@@ -294,12 +294,19 @@ OP_RETURN {
             ops = fframe->orig_ops;
             // printf("RETURN :orig: %d, current: %d\n", fframe->top, stack.size());
 
+            while (stack.size() > frame->top) {
+                stack.pop();
+            }
+
             frame_stack->pop_back();
 
             stack.push(retval);
             break;
         } else {
             // printf("THIS IS NOT A FUNCTION FRAME\n");
+            while (stack.size() > frame->top) {
+                stack.pop();
+            }
             frame_stack->pop_back();
         }
     }
@@ -313,11 +320,9 @@ OP_ENTER {
 
 OP_LEAVE {
     SharedPtr<LexicalVarsFrame> frame = frame_stack->back();
-    /*
     while (stack.size() > frame->top) {
         stack.pop();
     }
-    */
     frame_stack->pop_back();
 }