diff --git a/synapse/http/site.py b/synapse/http/site.py
index f0828c654243229f60993757d70ab391e85c3207..18f2d37e00a742045257bf99bd769bbaacf4e2fc 100644
--- a/synapse/http/site.py
+++ b/synapse/http/site.py
@@ -85,7 +85,7 @@ class SynapseRequest(Request):
         return "%s-%i" % (self.method, self.request_seq)
 
     def get_redacted_uri(self):
-        return redact_uri(self.uri)
+        return redact_uri(self.uri.decode('ascii'))
 
     def get_user_agent(self):
         return self.requestHeaders.getRawHeaders(b"User-Agent", [None])[-1]