diff --git a/django/core/validators.py b/django/core/validators.py
index 948ae28673..3067b551da 100644
--- a/django/core/validators.py
+++ b/django/core/validators.py
@@ -50,6 +50,7 @@ class URLValidator(RegexValidator):
         r'\[?[A-F0-9]*:[A-F0-9:]+\]?)'  # ...or ipv6
         r'(?::\d+)?'  # optional port
         r'(?:/?|[/?]\S+)$', re.IGNORECASE)
+    message = _('Enter a valid URL.')
 
     def __call__(self, value):
         try:
diff --git a/tests/validation/tests.py b/tests/validation/tests.py
index 58b7b94e7f..ed9ca96bc6 100644
--- a/tests/validation/tests.py
+++ b/tests/validation/tests.py
@@ -55,7 +55,7 @@ class BaseModelValidationTests(ValidationTestCase):
 
     def test_wrong_url_value_raises_error(self):
         mtv = ModelToValidate(number=10, name='Some Name', url='not a url')
-        self.assertFieldFailsValidationWithMessage(mtv.full_clean, 'url', ['Enter a valid value.'])
+        self.assertFieldFailsValidationWithMessage(mtv.full_clean, 'url', ['Enter a valid URL.'])
 
     def test_text_greater_that_charfields_max_length_raises_erros(self):
         mtv = ModelToValidate(number=10, name='Some Name'*100)