diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 017f55adf4..9fd09dbe93 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -23,16 +23,6 @@ prompt_given ()
test "$prompt" = "Launch 'test-tool' [Y/n]: branch"
}
-stdin_contains ()
-{
- grep >/dev/null "$1"
-}
-
-stdin_doesnot_contain ()
-{
- ! stdin_contains "$1"
-}
-
# Create a file on master and change it on branch
test_expect_success PERL 'setup' '
echo master >file &&
@@ -296,24 +286,24 @@ test_expect_success PERL 'setup with 2 files different' '
test_expect_success PERL 'say no to the first file' '
(echo n && echo) >input &&
git difftool -x cat branch output &&
- stdin_contains m2