diff --git a/components/net_traits/lib.rs b/components/net_traits/lib.rs
index f5e70489fd4..51695e0c980 100644
--- a/components/net_traits/lib.rs
+++ b/components/net_traits/lib.rs
@@ -46,7 +46,7 @@ pub mod storage_task;
 
 pub static IPV4_REGEX: Regex = regex!(
     r"^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$");
-pub static IPV6_REGEX: Regex = regex!(r"^([a-fA-F0-9]{0,4}[:]?){1,8}(/\d{1,3})?$");
+pub static IPV6_REGEX: Regex = regex!(r"^([a-fA-F0-9]{0,4}[:]?){1,8}$");
 
 /// [Response type](https://fetch.spec.whatwg.org/#concept-response-type)
 #[derive(Clone, PartialEq, Copy)]
diff --git a/tests/unit/net/resource_task.rs b/tests/unit/net/resource_task.rs
index c72dc66ba22..70e58fd58b2 100644
--- a/tests/unit/net/resource_task.rs
+++ b/tests/unit/net/resource_task.rs
@@ -121,12 +121,9 @@ fn test_parse_hostsfile_with_valid_ipv6_addresses()
                                    0000:0000:0000:0000:0000:0000:0000:0001 bar.moz.com\n\
                                    ::1 foo.bar.baz baz.foo.com\n\
                                    2001:0DB8:85A3:0042:1000:8A2E:0370:7334 baz.bar.moz\n\
-                                   2002:0DB8:85A3:0042:1000:8A2E:0370:7334/96 baz2.bar.moz\n\
-                                   2002:0DB8:85A3:0042:1000:8A2E:0370:7334/128 baz3.bar.moz\n\
-                                   :: unspecified.moz.com\n\
-                                   ::/128 unspecified.address.com";
+                                   :: unspecified.moz.com";
     let hosts_table = parse_hostsfile(mock_hosts_file_content);
-    assert_eq!(12, (*hosts_table).len());
+    assert_eq!(9, (*hosts_table).len());
 }
 
 #[test]