diff --git a/common.h b/common.h
index df58ebf..4a2e006 100644
--- a/common.h
+++ b/common.h
@@ -200,7 +200,7 @@ extern struct addrinfo *addr_listen;
 extern const char* server_type;
 
 #if defined(__APPLE__) && (MAC_OS_X_VERSION_MIN_REQUIRED < 1080)
-extern int hosts_ctl();
+extern int hosts_ctl(char*, char*, char*, char*);
 #endif
 
 /* sslh-fork.c */