diff --git a/bin/kenv/kenv.c b/bin/kenv/kenv.c
index dc86ba8200a9..6c59b2cdce92 100644
--- a/bin/kenv/kenv.c
+++ b/bin/kenv/kenv.c
@@ -118,7 +118,7 @@ main(int argc, char **argv)
 }
 
 static int
-kdumpenv()
+kdumpenv(void)
 {
 	char *buf, *cp;
 	int buflen, envlen;