diff --git a/tests/sys/net/if_ovpn/if_ovpn_c.c b/tests/sys/net/if_ovpn/if_ovpn_c.c
index 44363620d277..d98f5a0dd8e6 100644
--- a/tests/sys/net/if_ovpn/if_ovpn_c.c
+++ b/tests/sys/net/if_ovpn/if_ovpn_c.c
@@ -16,7 +16,7 @@
 #define OVPN_NEW_PEER		_IO  ('D', 1)
 
 static nvlist_t *
-fake_sockaddr()
+fake_sockaddr(void)
 {
 	uint32_t addr = htonl(INADDR_LOOPBACK);
 	nvlist_t *nvl;