diff --git a/lib/libspl/os/linux/zone.c b/lib/libspl/os/linux/zone.c
index a71c4e0b275b..393a16ad5cdd 100644
--- a/lib/libspl/os/linux/zone.c
+++ b/lib/libspl/os/linux/zone.c
@@ -26,7 +26,7 @@
 #include <zone.h>
 
 zoneid_t
-getzoneid()
+getzoneid(void)
 {
 	return (GLOBAL_ZONEID);
 }