diff --git a/src/test/regress/.gitignore b/src/test/regress/.gitignore
index 42f938a46..e5da6ab73 100644
--- a/src/test/regress/.gitignore
+++ b/src/test/regress/.gitignore
@@ -22,3 +22,7 @@
 
 # python
 *.pyc
+
+# output from diff normalization that shouldn't be commited
+*.unmodified
+*.modified