diff --git a/snake.go b/snake.go
index 30223f4..159c1b5 100644
--- a/snake.go
+++ b/snake.go
@@ -78,8 +78,8 @@ func ToScreamingDelimited(s string, delimiter uint8, ignore uint8, screaming boo
 			// add underscore if next letter case type is changed
 			if (vIsCap && nextIsLow) || (vIsLow && nextIsCap) {
 				if prevIgnore := ignore > 0 && i > 0 && s[i-1] == ignore; !prevIgnore {
-					if i > 0 && vIsCap && nextIsLow {
-						if prevDelim := len(n) > 0 && n[len(n)-1] == delimiter; !prevDelim {
+					if vIsCap && nextIsLow {
+						if prevIsCap := i > 0 && s[i-1] >= 'A' && s[i-1] <= 'Z'; prevIsCap {
 							n += string(delimiter)
 						}
 					}
diff --git a/snake_test.go b/snake_test.go
index 7f89e4b..5482999 100644
--- a/snake_test.go
+++ b/snake_test.go
@@ -84,7 +84,7 @@ func toSnakeWithIgnore(tb testing.TB) {
 		{"JSONData", "json_data"},
 		{"AwesomeActivity.UserID", "awesome_activity.user_id", "."},
 		{"AwesomeActivity.User.Id", "awesome_activity.user.id", "."},
-		{"AwesomeUsername@Awesome.Com", "awesome_username@awesome._com", "@"},
+		{"AwesomeUsername@Awesome.Com", "awesome_username@awesome.com", "@"},
 	}
 	for _, i := range cases {
 		in := i[0]