diff --git a/GPU/Common/VertexDecoderArm.cpp b/GPU/Common/VertexDecoderArm.cpp
index 90b405b81b..17454f6fff 100644
--- a/GPU/Common/VertexDecoderArm.cpp
+++ b/GPU/Common/VertexDecoderArm.cpp
@@ -20,6 +20,8 @@
 #define ARM
 #endif
 
+#include <stddef.h>
+
 #include "base/logging.h"
 #include "Common/CPUDetect.h"
 #include "Core/Config.h"