diff --git a/zfs/lib/libspl/include/sys/zfs_context.h b/zfs/lib/libspl/include/sys/zfs_context.h
index 6c3fb41c93..0328e22eb9 100644
--- a/zfs/lib/libspl/include/sys/zfs_context.h
+++ b/zfs/lib/libspl/include/sys/zfs_context.h
@@ -71,6 +71,7 @@ extern "C" {
 #include <sys/sdt.h>
 #include <sys/kstat.h>
 #include <sys/u8_textprep.h>
+#include <sys/va_list.h>
 #include <sys/sysevent/eventdefs.h>
 
 /*
diff --git a/zfs/lib/libspl/kernel.c b/zfs/lib/libspl/kernel.c
index fe18b414bd..9d2a79a4e9 100644
--- a/zfs/lib/libspl/kernel.c
+++ b/zfs/lib/libspl/kernel.c
@@ -55,7 +55,7 @@ struct utsname utsname = {
  */
 /*ARGSUSED*/
 kthread_t *
-zk_thread_create(void (*func)(), void *arg)
+zk_thread_create(void (*func)(void), void *arg)
 {
 	pthread_t tid;