diff --git a/usr.sbin/mixer/mixer.c b/usr.sbin/mixer/mixer.c
--- a/usr.sbin/mixer/mixer.c
+++ b/usr.sbin/mixer/mixer.c
@@ -30,9 +30,11 @@
 #include <string.h>
 #include <unistd.h>
 
-#define C_VOL 0
-#define C_MUT 1
-#define C_SRC 2
+enum {
+	C_VOL = 0,
+	C_MUT,
+	C_SRC,
+};
 
 static void usage(void) __dead2;
 static void initctls(struct mixer *);