diff --git a/utils/osmo-aka-verify.c b/utils/osmo-aka-verify.c
index bbc65ef..f23c349 100644
--- a/utils/osmo-aka-verify.c
+++ b/utils/osmo-aka-verify.c
@@ -88,7 +88,7 @@
 }
 
 
-static void help()
+static void help(void)
 {
 	printf( "Static SIM card parameters:\n"
 		"-k  --key\tSpecify Ki / K\n"
diff --git a/utils/osmo-auc-gen.c b/utils/osmo-auc-gen.c
index 72f1fcd..e3e1b43 100644
--- a/utils/osmo-auc-gen.c
+++ b/utils/osmo-auc-gen.c
@@ -85,7 +85,7 @@
 	.algo = OSMO_AUTH_ALG_NONE,
 };
 
-static void help()
+static void help(void)
 {
 	int alg;
 	printf( "-2  --2g\tUse 2G (GSM) authentication\n"
diff --git a/utils/osmo-ns-dummy.c b/utils/osmo-ns-dummy.c
index 0af1a89..eabe008 100644
--- a/utils/osmo-ns-dummy.c
+++ b/utils/osmo-ns-dummy.c
@@ -43,7 +43,7 @@
 	.copyright	= vty_copyright,
 };
 
-static void print_help()
+static void print_help(void)
 {
 	printf( "Some useful options:\n"
 		"  -h	--help			This text\n"