diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index cf5b6d7ef7..8cb83195a8 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -2382,12 +2382,12 @@ class UUIDField(Field):
         return "UUIDField"
 
     def get_db_prep_value(self, value, connection, prepared=False):
+        if isinstance(value, six.string_types):
+            value = uuid.UUID(value.replace('-', ''))
         if isinstance(value, uuid.UUID):
             if connection.features.has_native_uuid_field:
                 return value
             return value.hex
-        if isinstance(value, six.string_types):
-            return value.replace('-', '')
         return value
 
     def to_python(self, value):
diff --git a/tests/model_fields/test_uuid.py b/tests/model_fields/test_uuid.py
index 4680d5dbb4..f06f4d02a7 100644
--- a/tests/model_fields/test_uuid.py
+++ b/tests/model_fields/test_uuid.py
@@ -34,6 +34,15 @@ class TestSaveLoad(TestCase):
         loaded = NullableUUIDModel.objects.get()
         self.assertEqual(loaded.field, None)
 
+    def test_wrong_value(self):
+        self.assertRaisesMessage(
+            ValueError, 'badly formed hexadecimal UUID string',
+            UUIDModel.objects.get, field='not-a-uuid')
+
+        self.assertRaisesMessage(
+            ValueError, 'badly formed hexadecimal UUID string',
+            UUIDModel.objects.create, field='not-a-uuid')
+
 
 class TestMigrations(TestCase):