diff --git a/rgw/admin/errors.go b/rgw/admin/errors.go
index edb4380..c97de7d 100644
--- a/rgw/admin/errors.go
+++ b/rgw/admin/errors.go
@@ -79,6 +79,9 @@ const (
 	// ErrUnknown - reports an unknown error
 	ErrUnknown errorReason = "Unknown"
 
+	// ErrSignatureDoesNotMatch - the query to the API has invalid parameters
+	ErrSignatureDoesNotMatch errorReason = "SignatureDoesNotMatch"
+
 	unmarshalError = "failed to unmarshal radosgw http response"
 )