diff --git a/Documentation/git-check-mailmap.txt b/Documentation/git-check-mailmap.txt
index 02f4418323..7747e38e25 100644
--- a/Documentation/git-check-mailmap.txt
+++ b/Documentation/git-check-mailmap.txt
@@ -15,10 +15,10 @@ SYNOPSIS
 DESCRIPTION
 -----------
 
-For each ``Name $$<user@host>$$'' or ``$$<user@host>$$'' from the command-line
-or standard input (when using `--stdin`), look up the person's canonical name
-and email address (see "Mapping Authors" below). If found, print them;
-otherwise print the input as-is.
+For each ``Name $$<user@host>$$'', ``$$<user@host>$$'', or ``$$user@host$$''
+from the command-line or standard input (when using `--stdin`), look up the
+person's canonical name and email address (see "Mapping Authors" below). If
+found, print them; otherwise print the input as-is.
 
 
 OPTIONS
diff --git a/builtin/check-mailmap.c b/builtin/check-mailmap.c
index b8a05b8e07..6b7fb53494 100644
--- a/builtin/check-mailmap.c
+++ b/builtin/check-mailmap.c
@@ -25,13 +25,17 @@ static void check_mailmap(struct string_list *mailmap, const char *contact)
 	size_t namelen, maillen;
 	struct ident_split ident;
 
-	if (split_ident_line(&ident, contact, strlen(contact)))
-		die(_("unable to parse contact: %s"), contact);
-
-	name = ident.name_begin;
-	namelen = ident.name_end - ident.name_begin;
-	mail = ident.mail_begin;
-	maillen = ident.mail_end - ident.mail_begin;
+	if (!split_ident_line(&ident, contact, strlen(contact))) {
+		name = ident.name_begin;
+		namelen = ident.name_end - ident.name_begin;
+		mail = ident.mail_begin;
+		maillen = ident.mail_end - ident.mail_begin;
+	} else {
+		name = NULL;
+		namelen = 0;
+		mail = contact;
+		maillen = strlen(contact);
+	}
 
 	map_user(mailmap, &mail, &maillen, &name, &namelen);
 
diff --git a/t/t4203-mailmap.sh b/t/t4203-mailmap.sh
index 8a88dd7900..2421491931 100755
--- a/t/t4203-mailmap.sh
+++ b/t/t4203-mailmap.sh
@@ -71,12 +71,46 @@ test_expect_success 'check-mailmap --stdin arguments: mapping' '
 	test_cmp expect actual
 '
 
-test_expect_success 'check-mailmap bogus contact' '
-	test_must_fail git check-mailmap bogus
+test_expect_success 'check-mailmap simple address: mapping' '
+	test_when_finished "rm .mailmap" &&
+	cat >.mailmap <<-EOF &&
+	New Name <$GIT_AUTHOR_EMAIL>
+	EOF
+	cat .mailmap >expect &&
+	git check-mailmap "$GIT_AUTHOR_EMAIL" >actual &&
+	test_cmp expect actual
 '
 
-test_expect_success 'check-mailmap bogus contact --stdin' '
-	test_must_fail git check-mailmap --stdin bogus </dev/null
+test_expect_success 'check-mailmap --stdin simple address: mapping' '
+	test_when_finished "rm .mailmap" &&
+	cat >.mailmap <<-EOF &&
+	New Name <$GIT_AUTHOR_EMAIL>
+	EOF
+	cat >stdin <<-EOF &&
+	$GIT_AUTHOR_EMAIL
+	EOF
+	cat .mailmap >expect &&
+	git check-mailmap --stdin <stdin >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check-mailmap simple address: no mapping' '
+	cat >expect <<-EOF &&
+	<bugs@company.xx>
+	EOF
+	git check-mailmap "bugs@company.xx" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check-mailmap --stdin simple address: no mapping' '
+	cat >expect <<-EOF &&
+	<bugs@company.xx>
+	EOF
+	cat >stdin <<-EOF &&
+	bugs@company.xx
+	EOF
+	git check-mailmap --stdin <stdin >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'No mailmap' '