diff --git a/etc/mtree/BSD.tests.dist b/etc/mtree/BSD.tests.dist
index aa50d6f6a53..9b7b26fe489 100644
--- a/etc/mtree/BSD.tests.dist
+++ b/etc/mtree/BSD.tests.dist
@@ -612,6 +612,8 @@
         ..
         cut
         ..
+        diff
+        ..
         dirname
         ..
         file2c