diff --git a/dir.c b/dir.c
index 130fa98766..465c22ff68 100644
--- a/dir.c
+++ b/dir.c
@@ -1369,6 +1369,12 @@ int match_pathname(const char *pathname, int pathlen,
 		if (patternlen == prefix && namelen == prefix)
 			return 1;
 
+		/*
+		 * Retain one character of the prefix to
+		 * pass to fnmatch, which lets it distinguish
+		 * the start of a directory component correctly.
+		 */
+		prefix--;
 		pattern += prefix;
 		patternlen -= prefix;
 		name    += prefix;
diff --git a/t/t0008-ignores.sh b/t/t0008-ignores.sh
index 273d71411f..db8bde280e 100755
--- a/t/t0008-ignores.sh
+++ b/t/t0008-ignores.sh
@@ -847,6 +847,17 @@ test_expect_success 'directories and ** matches' '
 	test_cmp expect actual
 '
 
+test_expect_success '** not confused by matching leading prefix' '
+	cat >.gitignore <<-\EOF &&
+	foo**/bar
+	EOF
+	git check-ignore foobar foo/bar >actual &&
+	cat >expect <<-\EOF &&
+	foo/bar
+	EOF
+	test_cmp expect actual
+'
+
 ############################################################################
 #
 # test whitespace handling