diff --git a/zfs/lib/libspl/kernel.c b/zfs/lib/libspl/kernel.c
index fe817cc64b..9740f1ba6e 100644
--- a/zfs/lib/libspl/kernel.c
+++ b/zfs/lib/libspl/kernel.c
@@ -56,7 +56,7 @@ struct utsname utsname = {
  */
 /*ARGSUSED*/
 kthread_t *
-zk_thread_create(void (*func)(), void *arg)
+zk_thread_create(void (*func)(void), void *arg)
 {
 	thread_t tid;