diff --git a/lib/providers/MongoDB.Provider.js b/lib/providers/MongoDB.Provider.js
index <HASH>..<HASH> 100644
--- a/lib/providers/MongoDB.Provider.js
+++ b/lib/providers/MongoDB.Provider.js
@@ -97,9 +97,11 @@ function MongoDB(config) {
 
 	// uniform error messages
 	this.missing_data_err = "Missing 'data' argument.";
-	this.missing_data_id_err = "Missing 'data._id' property.";
+	this.missing_data_id_err = "Missing 'data._id' argument.";
 	this.missing_key_err = "Missing 'key' argument.";
 	this.missing_callback_err = "Missing 'callback' argument.";
+	this.callback_not_an_Object_err = "Argument 'data' must be of type Object.";
+	this.callback_not_an_Array_err = "Argument 'data' must be of type Array.";
 	this.callback_not_a_function_err = "Argument 'callback' must be of type Function.";
 
 	this.no_connection_err = "There is no open connection to the dabase server. Call connect function first.";
Renamed and added new error constant messages