diff --git a/src/shared/mount-util.c b/src/shared/mount-util.c
index b7ac03f5ae..e497035d41 100644
--- a/src/shared/mount-util.c
+++ b/src/shared/mount-util.c
@@ -1067,7 +1067,7 @@ finish:
 }
 
 static int mount_in_namespace(
-                PidRef *target,
+                const PidRef *target,
                 const char *propagate_path,
                 const char *incoming_path,
                 const char *src,