diff --git a/reactos/include/reactos/asm.h b/reactos/include/reactos/asm.h
index 30afca482a0..f60a37c79ef 100644
--- a/reactos/include/reactos/asm.h
+++ b/reactos/include/reactos/asm.h
@@ -73,7 +73,7 @@ ENDM
 .altmacro
 
 /* Hex numbers need to be in 0x1AB format */
-#define HEX(x) 0x##x
+#define HEX(y) 0x##y
 
 /* Macro values need to be marked */
 #define VAL(x) \x