diff --git a/examples/42_fused_multi_head_attention/kernel_forward.h b/examples/42_fused_multi_head_attention/kernel_forward.h
index 51dbbb06..fb0855d5 100644
--- a/examples/42_fused_multi_head_attention/kernel_forward.h
+++ b/examples/42_fused_multi_head_attention/kernel_forward.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #ifdef HAS_PYTORCH
 #include <ATen/ATen.h>
 #include <ATen/cuda/CUDAContext.h>