diff --git a/dnn/src/common/elemwise/opr_impl.cpp b/dnn/src/common/elemwise/opr_impl.cpp
index ed994866..b5981b8c 100644
--- a/dnn/src/common/elemwise/opr_impl.cpp
+++ b/dnn/src/common/elemwise/opr_impl.cpp
@@ -141,7 +141,10 @@ const ModeTrait& ModeTrait::from_mode(Mode mode) {
 #pragma message "elemwise mode stripped"
 #endif
     }
-
+    megdnn_assert(
+            static_cast<std::size_t>(mode) < traits.size(),
+            "Invalid elemwise mode in this version. "
+            "Maybe this version is too old, and you may need to update.");
     auto&& ret = traits.at(static_cast<int>(mode));
 #if !MEGDNN_ELEMWISE_MODE_ENABLE_ALL
     megdnn_assert(ret.arity);
diff --git a/dnn/src/common/elemwise_multi_type/opr_impl.cpp b/dnn/src/common/elemwise_multi_type/opr_impl.cpp
index f5bc9ec1..01acea16 100644
--- a/dnn/src/common/elemwise_multi_type/opr_impl.cpp
+++ b/dnn/src/common/elemwise_multi_type/opr_impl.cpp
@@ -274,7 +274,10 @@ const ModeTrait& ModeTrait::from_mode(Mode mode) {
         SET(init_bool_unary_op, ISINF);
 #undef SET
     }
-
+    megdnn_assert(
+            static_cast<std::size_t>(mode) < traits.size(),
+            "Invalid elemwise multitype mode in this version. "
+            "Maybe this version is too old, and you may need to update.");
     return traits.at(static_cast<int>(mode));
 }