diff --git a/synapse/rest/media/v1/upload_resource.py b/synapse/rest/media/v1/upload_resource.py

index e73e431dc9..97548b54e5 100644
--- a/synapse/rest/media/v1/upload_resource.py
+++ b/synapse/rest/media/v1/upload_resource.py
@@ -101,6 +101,8 @@ class UploadResource(DirectServeJsonResource):
             # the default 404, as that would just be confusing.
             raise SynapseError(400, "Bad content")
 
-        logger.info("Uploaded content with URI %r", content_uri)
+        logger.info("Uploaded content with URI '%s'", content_uri)
 
-        respond_with_json(request, 200, {"content_uri": content_uri}, send_cors=True)
+        respond_with_json(
+            request, 200, {"content_uri": str(content_uri)}, send_cors=True
+        )