diff --git a/mailmap.c b/mailmap.c
index 44614fc411..3061434321 100644
--- a/mailmap.c
+++ b/mailmap.c
@@ -193,20 +193,17 @@ static int read_mailmap_file(struct string_list *map, const char *filename,
 	return 0;
 }
 
-static void read_mailmap_buf(struct string_list *map,
-			     const char *buf, unsigned long len,
-			     char **repo_abbrev)
+static void read_mailmap_string(struct string_list *map, char *buf,
+				char **repo_abbrev)
 {
-	while (len) {
-		const char *end = strchrnul(buf, '\n');
-		unsigned long linelen = end - buf + 1;
-		char *line = xmemdupz(buf, linelen);
+	while (*buf) {
+		char *end = strchrnul(buf, '\n');
 
-		read_mailmap_line(map, line, repo_abbrev);
+		if (*end)
+			*end++ = '\0';
 
-		free(line);
-		buf += linelen;
-		len -= linelen;
+		read_mailmap_line(map, buf, repo_abbrev);
+		buf = end;
 	}
 }
 
@@ -230,7 +227,7 @@ static int read_mailmap_blob(struct string_list *map,
 	if (type != OBJ_BLOB)
 		return error("mailmap is not a blob: %s", name);
 
-	read_mailmap_buf(map, buf, size, repo_abbrev);
+	read_mailmap_string(map, buf, repo_abbrev);
 
 	free(buf);
 	return 0;
diff --git a/t/t4203-mailmap.sh b/t/t4203-mailmap.sh
index baa4685dcc..ce3eace065 100755
--- a/t/t4203-mailmap.sh
+++ b/t/t4203-mailmap.sh
@@ -202,7 +202,8 @@ test_expect_success 'setup mailmap blob tests' '
 	Blob Guy <author@example.com>
 	Blob Guy <bugs@company.xx>
 	EOF
-	git add just-bugs both &&
+	printf "Tricky Guy <author@example.com>" >no-newline &&
+	git add just-bugs both no-newline &&
 	git commit -m "my mailmaps" &&
 	echo "Repo Guy <author@example.com>" >.mailmap &&
 	echo "Internal Guy <author@example.com>" >internal.map
@@ -286,6 +287,19 @@ test_expect_success 'mailmap.blob defaults to HEAD:.mailmap in bare repo' '
 	)
 '
 
+test_expect_success 'mailmap.blob can handle blobs without trailing newline' '
+	cat >expect <<-\EOF &&
+	Tricky Guy (1):
+	      initial
+
+	nick1 (1):
+	      second
+
+	EOF
+	git -c mailmap.blob=map:no-newline shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'cleanup after mailmap.blob tests' '
 	rm -f .mailmap
 '