diff --git a/src/gfx_compilers.h b/src/gfx_compilers.h
index d29f92a7..925fc9bd 100644
--- a/src/gfx_compilers.h
+++ b/src/gfx_compilers.h
@@ -332,6 +332,7 @@
 		#define GFX_COMPILER_VERSION_PATCH			((__CC65__)%0x10)
 	#elif GFX_COMPILER == GFX_COMPILER_CLANG
 		#define GFX_COMPILER_NAME					"CLang (LLVM)"
+		#define GFX_COMPILER_TESTED					TRUE
 		#define GFX_COMPILER_VERSION_MAJOR			(__clang_major__)
 		#define GFX_COMPILER_VERSION_MINOR			(__clang_minor__)
 		#define GFX_COMPILER_VERSION_PATCH			(__clang_patchlevel__)