diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index 781af2e48..d340d16e4 100755
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -547,8 +547,12 @@ class ResponseObject(_TemplateEnvironmentMixin):
         # ACL and checking for the mere presence of an Authorization
         # header.
         if 'Authorization' not in request.headers:
+            if hasattr(request, 'url'):
+                signed_url = 'Signature=' in request.url
+            elif hasattr(request, 'requestline'):
+                signed_url = 'Signature=' in request.path
             key = self.backend.get_key(bucket_name, key_name)
-            signed_url = 'Signature=' in request.url
+
             if key:
                 if not key.acl.public_read and not signed_url:
                     return 403, {}, ""