diff --git a/opencontainers/distribution/reggie/defaults.py b/opencontainers/distribution/reggie/defaults.py
index 8b43fb9..d7aa151 100644
--- a/opencontainers/distribution/reggie/defaults.py
+++ b/opencontainers/distribution/reggie/defaults.py
@@ -14,6 +14,6 @@
     __version__
 )
 URL_REGEX = (
-    "http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+"
+    "http[s]?:\/\/(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+"
 )
 VALID_METHODS = ["HEAD", "GET", "POST", "PATCH", "PUT", "DELETE", "OPTIONS"]
diff --git a/opencontainers/tests/test_descriptor.py b/opencontainers/tests/test_descriptor.py
index ebb0512..07b3a1b 100644
--- a/opencontainers/tests/test_descriptor.py
+++ b/opencontainers/tests/test_descriptor.py
@@ -137,7 +137,7 @@
     {
         "mediaType": "application/vnd.oci.image.config.v1+json",
         "size": 1470,
-        "digest": "sha256.foo-bar:c86f7763873b6c0aae22d963bab59b4f5debbed6685761b5951584f6efb0633b"
+        "digest": "sha256.foo-bar:c86f7763873b6c0aae22d963bab59b4f5debbed6685761b5951584f6efb0633b",
         # multihash example removed, not supported is invalid
     },
 ]
diff --git a/opencontainers/tests/test_manifest.py b/opencontainers/tests/test_manifest.py
index 6fc7b84..2aec60b 100644
--- a/opencontainers/tests/test_manifest.py
+++ b/opencontainers/tests/test_manifest.py
@@ -140,7 +140,7 @@
             "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
             "size": 1470,
             "digest": "sha256.foo-bar:c86f7763873b6c0aae22d963bab59b4f5debbed6685761b5951584f6efb0633b",
-        }
+        },
         # multihash is not registered, but still valid formatting, but here we would consider it invalid
         # {
         #  "mediaType": "application/vnd.oci.image.config.v1+json",