diff --git a/onnxruntime/core/optimizer/matmul_scale_fusion.h b/onnxruntime/core/optimizer/matmul_scale_fusion.h
index 64f33f59df0c7..7fd757b430ecb 100644
--- a/onnxruntime/core/optimizer/matmul_scale_fusion.h
+++ b/onnxruntime/core/optimizer/matmul_scale_fusion.h
@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+#pragma once
+
 #include "core/optimizer/graph_transformer.h"
 
 namespace onnxruntime {