diff --git a/main/src/io/github/iltotore/iron/constraint/string.scala b/main/src/io/github/iltotore/iron/constraint/string.scala
index 6b6481aa..a8d36433 100644
--- a/main/src/io/github/iltotore/iron/constraint/string.scala
+++ b/main/src/io/github/iltotore/iron/constraint/string.scala
@@ -72,7 +72,7 @@ object string:
    */
   type ValidURL =
     Match[
-      "((\\w+:)+\\/\\/)?(([-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,6})|(localhost))(:\\d{1,5})?(\\/|\\/([-a-zA-Z0-9@:%_\\+.~#?&//=]*))?"
+      "((\\w+:)+\\/\\/)?(([-a-zA-Z0-9@:%._\\+~#=]{2,256}\\.[a-z]{2,63})|(localhost))(:\\d{1,5})?(\\/|\\/([-a-zA-Z0-9@:%_\\+.~#?&//=]*))?"
     ] DescribedAs "Should be an URL"
 
   /**
diff --git a/main/test/src/io/github/iltotore/iron/testing/StringSuite.scala b/main/test/src/io/github/iltotore/iron/testing/StringSuite.scala
index f12993ba..2f847996 100644
--- a/main/test/src/io/github/iltotore/iron/testing/StringSuite.scala
+++ b/main/test/src/io/github/iltotore/iron/testing/StringSuite.scala
@@ -64,6 +64,7 @@ object StringSuite extends TestSuite:
       test - "http://example.com/#section".assertRefine[ValidURL]
       test - "http://example.com/?q=with%20space".assertRefine[ValidURL]
       test - "http://example.com/?q=with+space".assertRefine[ValidURL]
+      test - "https://aaaaa-bbb-cccccc-dddddddd.eeeeeeee-fff.ggg.hhhhhhhhh:1234".assertRefine[ValidURL]
       test - "/example.com".assertNotRefine[ValidURL]
       test - "://example.com".assertNotRefine[ValidURL]
       test - "http:///".assertNotRefine[ValidURL]