diff --git a/ctms/schemas/newsletter.py b/ctms/schemas/newsletter.py
index 5051b693..1feed151 100644
--- a/ctms/schemas/newsletter.py
+++ b/ctms/schemas/newsletter.py
@@ -1,7 +1,7 @@
 from datetime import datetime, timezone
 from typing import Literal, Optional
 
-from pydantic import Field, HttpUrl
+from pydantic import AnyUrl, Field
 
 from .base import ComparableBase
 
@@ -25,7 +25,7 @@ class NewsletterBase(ComparableBase):
         max_length=5,
         description="Newsletter language code, usually 2 lowercase letters",
     )
-    source: Optional[HttpUrl] = Field(
+    source: Optional[AnyUrl] = Field(
         default=None,
         description="Source URL of subscription",
         example="https://www.mozilla.org/en-US/",
diff --git a/tests/unit/test_schema_contact.py b/tests/unit/test_schema_contact.py
index bffe554f..7f041344 100644
--- a/tests/unit/test_schema_contact.py
+++ b/tests/unit/test_schema_contact.py
@@ -37,3 +37,9 @@ def test_unsubscribe_not_idempotent_equal():
     data["newsletters"][0]["subscribed"] = True
     modified = ContactInSchema(**data)
     assert not original.idempotent_equal(modified)
+
+
+def test_source_url_supports_localhost():
+    data = SAMPLE_MAXIMAL.dict()
+    data["newsletters"][0]["source"] = "http://localhost:8888/v1"
+    ContactInSchema(**data)