diff --git a/benchmarks/sum.py b/benchmarks/sum.py
new file mode 100644
index 00000000..a4382c09
--- /dev/null
+++ b/benchmarks/sum.py
@@ -0,0 +1,6 @@
+def f(n):
+    if n == 0:
+        return 0
+    return n + f(n-1)
+
+assert f(900) == 405450
\ No newline at end of file
diff --git a/src/vm.h b/src/vm.h
index 39054278..cb82baca 100644
--- a/src/vm.h
+++ b/src/vm.h
@@ -897,7 +897,9 @@ inline PyObject* VM::_exec(){
     bool need_raise = false;
 
     while(true){
+#if DEBUG_EXTRA_CHECK
         if(frame->id < base_id) UNREACHABLE();
+#endif
         try{
             if(need_raise){ need_raise = false; _raise(); }
             PyObject* ret = run_frame(frame);