diff --git a/src/runtime/cgo/gcc_libinit.c b/src/runtime/cgo/gcc_libinit.c
index 3dc5bde4ccb..3dafd10b7bc 100644
--- a/src/runtime/cgo/gcc_libinit.c
+++ b/src/runtime/cgo/gcc_libinit.c
@@ -63,7 +63,7 @@ _cgo_wait_runtime_init_done() {
 }
 
 void
-x_cgo_notify_runtime_init_done(void* dummy) {
+x_cgo_notify_runtime_init_done(void* dummy __attribute__ ((unused))) {
 	pthread_mutex_lock(&runtime_init_mu);
 	runtime_init_done = 1;
 	pthread_cond_broadcast(&runtime_init_cond);