diff --git a/re_test.go b/re_test.go
index 76d3524..6cb59bf 100644
--- a/re_test.go
+++ b/re_test.go
@@ -191,29 +191,30 @@ var reTests = []struct {
 
 var groupTests = []struct {
 	re     string
+	flags  []ReFlag
 	str    string
 	result []Match
 }{
-	{"(a)(b)", "ab", []Match{[]Group{{0, 2}, {0, 1}, {1, 2}}}},
-	{"((a))(b)", "ab", []Match{[]Group{{0, 2}, {0, 1}, {0, 1}, {1, 2}}}},
-	{"(0)", "ab", []Match{[]Group{}}},
-	{"(a)b", "ab", []Match{[]Group{{0, 2}, {0, 1}}}},
-	{"a(b)", "ab", []Match{[]Group{{0, 2}, {1, 2}}}},
-	{"(a|b)", "ab", []Match{[]Group{{0, 1}, {0, 1}}, []Group{{1, 2}, {1, 2}}}},
-	{"(a)|(b)", "ab", []Match{[]Group{{0, 1}, {0, 1}, {-1, -1}}, []Group{{1, 2}, {-1, -1}, {1, 2}}}},
-	{"(a+)(a)", "aaaa", []Match{[]Group{{0, 4}, {0, 3}, {3, 4}}}},
-	{"(a+)|(a)", "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
-	{"(a+)(aa)", "aaaa", []Match{[]Group{{0, 4}, {0, 2}, {2, 4}}}},
-	{"(aaaa)|(aaaa)", "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
-	{"(aaa)|(aaaa)", "aaaa", []Match{[]Group{{0, 4}, {-1, -1}, {0, 4}}}},
-	{"(aaa)|(aaaa)", "aaaa", []Match{[]Group{{0, 4}, {-1, -1}, {0, 4}}}},
-	{"(aaaa)|(aaa)", "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
-	{"(a)|(aa)", "aa", []Match{[]Group{{0, 2}, {-1, -1}, {0, 2}}}},
-	{"(a?)a?", "b", []Match{[]Group{{0, 0}, {0, 0}}, []Group{{1, 1}, {1, 1}}}},
-	{"(a?)a?", "ab", []Match{[]Group{{0, 1}, {0, 1}}, []Group{{1, 1}, {1, 1}}, []Group{{2, 2}, {2, 2}}}},
-	{"(a?)a?", "aa", []Match{[]Group{{0, 2}, {0, 1}}, []Group{{2, 2}, {2, 2}}}},
-	{"a((b.d){3})", "abfdbhdbid", []Match{[]Group{{0, 10}, {1, 10}, {7, 10}}}},
-	{`(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)\071`, `abcdefghijkl9`, []Match{[]Group{{0, 13}, {0, 1}, {1, 2}, {2, 3}, {3, 4}, {4, 5}, {5, 6}, {6, 7}, {7, 8}, {8, 9}, {9, 10}, {10, 11}, {11, 12}}}},
+	{"(a)(b)", nil, "ab", []Match{[]Group{{0, 2}, {0, 1}, {1, 2}}}},
+	{"((a))(b)", nil, "ab", []Match{[]Group{{0, 2}, {0, 1}, {0, 1}, {1, 2}}}},
+	{"(0)", nil, "ab", []Match{[]Group{}}},
+	{"(a)b", nil, "ab", []Match{[]Group{{0, 2}, {0, 1}}}},
+	{"a(b)", nil, "ab", []Match{[]Group{{0, 2}, {1, 2}}}},
+	{"(a|b)", nil, "ab", []Match{[]Group{{0, 1}, {0, 1}}, []Group{{1, 2}, {1, 2}}}},
+	{"(a)|(b)", nil, "ab", []Match{[]Group{{0, 1}, {0, 1}, {-1, -1}}, []Group{{1, 2}, {-1, -1}, {1, 2}}}},
+	{"(a+)(a)", nil, "aaaa", []Match{[]Group{{0, 4}, {0, 3}, {3, 4}}}},
+	{"(a+)|(a)", nil, "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
+	{"(a+)(aa)", nil, "aaaa", []Match{[]Group{{0, 4}, {0, 2}, {2, 4}}}},
+	{"(aaaa)|(aaaa)", nil, "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
+	{"(aaa)|(aaaa)", nil, "aaaa", []Match{[]Group{{0, 4}, {-1, -1}, {0, 4}}}},
+	{"(aaa)|(aaaa)", nil, "aaaa", []Match{[]Group{{0, 4}, {-1, -1}, {0, 4}}}},
+	{"(aaaa)|(aaa)", nil, "aaaa", []Match{[]Group{{0, 4}, {0, 4}, {-1, -1}}}},
+	{"(a)|(aa)", nil, "aa", []Match{[]Group{{0, 2}, {-1, -1}, {0, 2}}}},
+	{"(a?)a?", nil, "b", []Match{[]Group{{0, 0}, {0, 0}}, []Group{{1, 1}, {1, 1}}}},
+	{"(a?)a?", nil, "ab", []Match{[]Group{{0, 1}, {0, 1}}, []Group{{1, 1}, {1, 1}}, []Group{{2, 2}, {2, 2}}}},
+	{"(a?)a?", nil, "aa", []Match{[]Group{{0, 2}, {0, 1}}, []Group{{2, 2}, {2, 2}}}},
+	{"a((b.d){3})", nil, "abfdbhdbid", []Match{[]Group{{0, 10}, {1, 10}, {7, 10}}}},
+	{`(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)\071`, nil, `abcdefghijkl9`, []Match{[]Group{{0, 13}, {0, 1}, {1, 2}, {2, 3}, {3, 4}, {4, 5}, {5, 6}, {6, 7}, {7, 8}, {8, 9}, {9, 10}, {10, 11}, {11, 12}}}},
 }
 
 func TestFindAllMatches(t *testing.T) {