diff --git a/src/mame/video/n64.h b/src/mame/video/n64.h
index 96a3069b321..262c1ebd068 100644
--- a/src/mame/video/n64.h
+++ b/src/mame/video/n64.h
@@ -40,7 +40,7 @@
 #define FORMAT_IA				3
 #define FORMAT_I				4
 
-#if LSB_FIRST
+#ifdef LSB_FIRST
 #define BYTE_XOR_DWORD_SWAP 7
 #define WORD_XOR_DWORD_SWAP 3
 #else