diff --git a/lib/cartodb/signed_maps.js b/lib/cartodb/signed_maps.js
index 4a62432f..6c4af8d3 100644
--- a/lib/cartodb/signed_maps.js
+++ b/lib/cartodb/signed_maps.js
@@ -94,6 +94,14 @@ o.authorizedByCert = function(cert, auth) {
     throw new Error("Unsupported certificate version " + cert.version);
   }
 
+  if ( ! cert.auth ) {
+    throw new Error("No certificate authorization");
+  }
+
+  if ( ! cert.auth.method ) {
+    throw new Error("No certificate authorization method");
+  }
+
   // Open authentication certificates are always authorized
   if ( cert.auth.method === 'open' ) return true;