diff --git a/tests/validators/tests.py b/tests/validators/tests.py
index 9256ed15ba..98da8b012c 100644
--- a/tests/validators/tests.py
+++ b/tests/validators/tests.py
@@ -294,6 +294,9 @@ TEST_DATA = [
     (validate_email, 'email@[2001:db8::12345]', ValidationError),
     (validate_email, 'email@[2001:db8:0:0:0:0:1]', ValidationError),
     (validate_email, 'email@[::ffff:127.0.0.256]', ValidationError),
+    (validate_email, 'email@[2001:dg8::1]', ValidationError),
+    (validate_email, 'email@[2001:dG8:0:0:0:0:0:1]', ValidationError),
+    (validate_email, 'email@[::fTzF:127.0.0.1]', ValidationError),
     (validate_email, 'example@invalid-.com', ValidationError),
     (validate_email, 'example@-invalid.com', ValidationError),
     (validate_email, 'example@invalid.com-', ValidationError),