diff --git a/Marlin/src/core/macros.h b/Marlin/src/core/macros.h
index 7a1bb45c5..961589dd3 100644
--- a/Marlin/src/core/macros.h
+++ b/Marlin/src/core/macros.h
@@ -56,7 +56,7 @@
 #define NANOSECONDS_PER_CYCLE (1000000000.0 / F_CPU)
 
 // Remove compiler warning on an unused variable
-#define UNUSED(x) ((void)(x))
+#define UNUSED(X) (void)X
 
 // Macros to make a string from a macro
 #define STRINGIFY_(M) #M