diff --git a/re_test.go b/re_test.go
index 65d2859..8a53720 100644
--- a/re_test.go
+++ b/re_test.go
@@ -149,14 +149,13 @@ var reTests = []struct {
 	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "400", []Group{{0, 3}}},
 	{"^((3[7-9])|([4-9][0-9])|([1-9][0-9][0-9])|(1000))$", "4000", []Group{}},
 
-	// Todo - add lookaround tests
+	// Lookaround tests
 	{"(?<=bo)y", "boy", []Group{{2, 3}}},
 	{"bo(?=y)", "boy", []Group{{0, 2}}},
-
-	// Todo - add numeric range tests
-	// Todo - add capturing group tests
 	{"(?<=f)f+(?=f)", "fffff", []Group{{1, 4}}},
 	{"(?<=f)f+(?=f)", "fffffa", []Group{{1, 4}}},
+
+	// Todo - add numeric range tests
 }
 
 var groupTests = []struct {
@@ -179,6 +178,9 @@ var groupTests = []struct {
 	{"(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}}}},
 }
 
 func TestFindAllMatches(t *testing.T) {