diff --git a/t/t7812-grep-icase-non-ascii.sh b/t/t7812-grep-icase-non-ascii.sh
index 9047d665a1..ac7be54714 100755
--- a/t/t7812-grep-icase-non-ascii.sh
+++ b/t/t7812-grep-icase-non-ascii.sh
@@ -4,6 +4,10 @@ test_description='grep icase on non-English locales'
 
 . ./lib-gettext.sh
 
+doalarm () {
+	perl -e 'alarm shift; exec @ARGV' -- "$@"
+}
+
 test_expect_success GETTEXT_LOCALE 'setup' '
 	test_write_lines "TILRAUN: Halló Heimur!" >file &&
 	git add file &&
@@ -139,4 +143,10 @@ test_expect_success GETTEXT_LOCALE,LIBPCRE2 'PCRE v2: grep non-literal ASCII fro
 	test_cmp expected actual
 '
 
+test_expect_success GETTEXT_LOCALE,LIBPCRE2 'PCRE v2: grep avoid endless loop bug' '
+	echo " Halló" >leading-whitespace &&
+	git add leading-whitespace &&
+	doalarm 1 git grep --perl-regexp "^\s" leading-whitespace
+'
+
 test_done