diff --git a/src/lib_base.c b/src/lib_base.c
index 0717ea86..5f7b059b 100644
--- a/src/lib_base.c
+++ b/src/lib_base.c
@@ -498,7 +498,7 @@ static int ffh_resume(lua_State *L, lua_State *co, int wrap)
     setstrV(L, L->base, lj_err_str(L, em));
     return FFH_RES(2);
   }
-  lj_state_growstack(co, (MSize)(L->top - L->base - 1));
+  lj_state_growstack(co, (MSize)(L->top - L->base));
   return FFH_RETRY;
 }