diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index ec2e4c9e71..a34432796b 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1759,6 +1759,7 @@ __git_diff_common_options="--stat --numstat --shortstat --summary
 			--patch --no-patch --cc --combined-all-paths
 			--anchored= --compact-summary --ignore-matching-lines=
 			--irreversible-delete --line-prefix --no-stat
+			--output=
 "
 
 # Options for diff/difftool