diff --git a/Makefile b/Makefile
index a6f3af7..06857bf 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ GCCVERSIONGTEQ4 := $(shell expr `gcc -dumpversion | cut -f1 -d.` \>= 4)
 ifeq ($(UNAME_S),Linux)
 	LIBS=-lrt
 else ifeq "$(GCCVERSIONGTEQ4)" "1"
-	CC=c99
+	CC?=c99
 endif
 
 OBJS=main.o init.o actions1.o actions2.o score.o misc.o