diff --git a/src/gallium/drivers/swr/rasterizer/common/os.h b/src/gallium/drivers/swr/rasterizer/common/os.h
index 7bfc66fde38..4076812e64a 100644
--- a/src/gallium/drivers/swr/rasterizer/common/os.h
+++ b/src/gallium/drivers/swr/rasterizer/common/os.h
@@ -24,6 +24,7 @@
 #ifndef __SWR_OS_H__
 #define __SWR_OS_H__
 
+#include <cstddef>
 #include "core/knobs.h"
 
 #if (defined(FORCE_WINDOWS) || defined(_WIN32)) && !defined(FORCE_LINUX)