diff --git a/Sources/API/Core/System/cl_assert.h b/Sources/API/Core/System/cl_assert.h
index ce4b07c..9d8b8b3 100644
--- a/Sources/API/Core/System/cl_assert.h
+++ b/Sources/API/Core/System/cl_assert.h
@@ -20,6 +20,7 @@
#define header_cl_assert
#include <list>
+#include <cstddef>
//: Error Channels Enum
enum ErrorChannels