diff --git a/resource/bluebird.js b/resource/bluebird.js
index 9765e3689f..9e2ae6677b 100644
--- a/resource/bluebird.js
+++ b/resource/bluebird.js
@@ -100,7 +100,7 @@
 			return;
 		}
 	
-		self.debug('Possibly unhandled rejection:\n\n' + e.message);
+		self.debug('Possibly unhandled rejection:\n\n' + (e.message || e));
 		throw e;
 	});
 	return;