diff --git a/Makefile b/Makefile
index f2a49073b..5682a387a 100644
--- a/Makefile
+++ b/Makefile
@@ -72,7 +72,7 @@ $(crystal11_obj):  RGBASMFLAGS += -D _CRYSTAL11
 $(crystal_au_obj): RGBASMFLAGS += -D _CRYSTAL11 -D _CRYSTAL_AU
 
 rgbdscheck.o: rgbdscheck.asm
-	$(RGMASM) -o $@ $<
+	$(RGBASM) -o $@ $<
 
 # The dep rules have to be explicit or else missing files won't be reported.
 # As a side effect, they're evaluated immediately instead of when the rule is invoked.