diff --git a/imperative/src/impl/proxy_graph.cpp b/imperative/src/impl/proxy_graph.cpp
index a449edffa61721737a4e583aaa676d7d3f90458f..f04a71190bcbd0a49ff28daf8b2604cb1d3a965b 100644
--- a/imperative/src/impl/proxy_graph.cpp
+++ b/imperative/src/impl/proxy_graph.cpp
@@ -376,6 +376,7 @@ public:
 
     ProxyGraphImpl(ProxyGraph* owner) : m_owner(owner) {
         options().imperative_proxy_graph = true;
+        options().no_force_inplace = true;
         options().log_level = 0;
         m_var_receiver_info.dev_value = 1;
         m_var_receiver_info.allow_empty_value = 1;
diff --git a/src/core/include/megbrain/graph/cg.h b/src/core/include/megbrain/graph/cg.h
index 7949b1c66ab1b67dde05f0ff67db15cce0f3a7fa..41c702eda3407abec789677f285e73e4951de577 100644
--- a/src/core/include/megbrain/graph/cg.h
+++ b/src/core/include/megbrain/graph/cg.h
@@ -464,6 +464,17 @@ class ComputingGraph : public std::enable_shared_from_this<ComputingGraph>,
 
             bool imperative_proxy_graph = false;
 
+            /*!
+             * Request that operators should not force update their inputs.
+             *
+             * THIS FLAG IS RESERVED FOR INTERNAL USE
+             *
+             * When this flag is set, operators like AddUpdate and BatchNorm
+             * will still attempt to inplace update their inputs, but failing
+             * to do so will not be considered as an error.
+             */
+            bool no_force_inplace = false;
+
             //! add extra deps for the comp seq if a specific var is dependent
             ThinHashMap<VarNode*, VarNodeArray> extra_vardeps;
 
diff --git a/src/opr/impl/dnn/batch_norm.cpp b/src/opr/impl/dnn/batch_norm.cpp
index a8daf566670f66709fd46d02e26f682ad03c8ab6..6461573bb38f0043c0774d711eb27d9086f08ba1 100644
--- a/src/opr/impl/dnn/batch_norm.cpp
+++ b/src/opr/impl/dnn/batch_norm.cpp
@@ -40,7 +40,7 @@ BatchNormForward::BatchNormForward(VarNode *x,
     Super{x->owner_graph(), config, "batch_norm",
           {x, scale, bias, mean, variance}}
 {
-    if(owner_graph()->options().imperative_proxy_graph) {
+    if(owner_graph()->options().no_force_inplace) {
         m_force_inplace = false;
     }