diff --git a/src/core/impl/graph/cg_impl.cpp b/src/core/impl/graph/cg_impl.cpp
index be9331c3..f49d9362 100644
--- a/src/core/impl/graph/cg_impl.cpp
+++ b/src/core/impl/graph/cg_impl.cpp
@@ -474,7 +474,7 @@ ComputingGraphImpl::CompileState ComputingGraphImpl::compile_prepare(
 #if MGB_ENABLE_SUBLINEAR
     if (options().enable_sublinear_memory_opt) {
         if (!sopr_stat.has_virtual_grad) {
-            mgb_log_warn(
+            mgb_log_debug(
                     "no virtual grad var; sublinear memory may produce "
                     "unsatisfying result");
         }