1 files changed, 1 insertions, 1 deletions
diff --git a/py/objfun.c b/py/objfun.c
index 8994486c85..732009376d 100644
--- a/py/objfun.c
+++ b/py/objfun.c
@@ -58,7 +58,7 @@ STATIC mp_obj_t fun_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
             // we don't even need to check for 2nd arg type.
             return MP_BOOL(lhs_in == rhs_in);
     }
-    return NULL;
+    return MP_OBJ_NOT_SUPPORTED;
 }
 
 STATIC mp_obj_t fun_native_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {