diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 99d4123461..77d58cf509 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -320,7 +320,7 @@ test_expect_success PERL 'difftool --extcmd cat arg1' '
 test_expect_success PERL 'difftool --extcmd cat arg2' '
 	echo branch >expect &&
 	git difftool --no-prompt \
-		--extcmd sh\ -c\ \"cat\ \$2\" branch >actual &&
+		--extcmd sh\ -c\ \"cat\ \\\"\$2\\\"\" branch >actual &&
 	test_cmp expect actual
 '