diff --git a/package/collection2/lib.js b/package/collection2/lib.js
index cade2b8..2ffb3b7 100644
--- a/package/collection2/lib.js
+++ b/package/collection2/lib.js
@@ -10,7 +10,7 @@ export function flattenSelector(selector) {
 
   const obj = {};
 
-  Object.entries(selector).forEach(([key, value]) => {
+  for (const [key, value] of Object.entries(selector) || []) {
     // Ignoring logical selectors (https://docs.mongodb.com/manual/reference/operator/query/#logical)
     if (!key.startsWith('$')) {
       if (typeof value === 'object' && value !== null) {
@@ -25,7 +25,7 @@ export function flattenSelector(selector) {
         obj[key] = value;
       }
     }
-  });
+  }
 
   return obj;
 }
diff --git a/package/collection2/main.js b/package/collection2/main.js
index d97041e..8d712df 100644
--- a/package/collection2/main.js
+++ b/package/collection2/main.js
@@ -117,7 +117,7 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
     Collection2.emit('schema.attached', this, ss, options);
   };
   
-  [Mongo.Collection, LocalCollection].forEach((obj) => {
+  for (const obj of [Mongo.Collection, LocalCollection]) {
     /**
      * simpleSchema
      * @description function detect the correct schema by given params. If it
@@ -132,7 +132,7 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
     obj.prototype.simpleSchema = function (doc, options, query) {
       if (!this._c2) return null;
       if (this._c2._simpleSchema) return this._c2._simpleSchema;
-  
+
       const schemas = this._c2._simpleSchemas;
       if (schemas && schemas.length > 0) {
         let schema, selector, target;
@@ -140,7 +140,7 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
         for (let i = 1; i < schemas.length; i++) {
           schema = schemas[i];
           selector = Object.keys(schema.selector)[0];
-  
+
           // We will set this to undefined because in theory, you might want to select
           // on a null value.
           target = undefined;
@@ -156,7 +156,7 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
             // on upsert/update operations
             target = query[selector];
           }
-  
+
           // we need to compare given selector with doc property or option to
           //  find the right schema
           if (target !== undefined && target === schema.selector[selector]) {
@@ -169,12 +169,12 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
           throw new Error('No default schema');
         }
       }
-  
+
       return null;
     };
-  });
+  }
 
-  function getArgumentsAndValidationContext(methodName, args, async) {
+function getArgumentsAndValidationContext(methodName, args, async) {
     let options = isInsertType(methodName) ? args[1] : args[2];
    
     // Support missing options arg
@@ -414,14 +414,12 @@ Mongo.Collection.prototype.attachSchema = function c2AttachSchema(ss, options) {
     };
   
     const cleanOptionsForThisOperation = {};
-    ['autoConvert', 'filter', 'removeEmptyStrings', 'removeNullsFromArrays', 'trimStrings'].forEach(
-      (prop) => {
-        if (typeof options[prop] === 'boolean') {
-          cleanOptionsForThisOperation[prop] = options[prop];
-        }
+    for (const prop of ['autoConvert', 'filter', 'removeEmptyStrings', 'removeNullsFromArrays', 'trimStrings']) {
+      if (typeof options[prop] === 'boolean') {
+        cleanOptionsForThisOperation[prop] = options[prop];
       }
-    );
-  
+    }
+
     // Preliminary cleaning on both client and server. On the server and for local
     // collections, automatic values will also be set at this point.
     schema.clean(doc, {
diff --git a/package/collection2/package.js b/package/collection2/package.js
index 3826f7e..022971b 100644
--- a/package/collection2/package.js
+++ b/package/collection2/package.js
@@ -4,7 +4,7 @@ Package.describe({
   name: 'aldeed:collection2',
   summary:
     'Automatic validation of Meteor Mongo insert and update operations on the client and server',
-  version: '4.0.3',
+  version: '4.0.4',
   documentation: '../../README.md',
   git: 'https://github.com/aldeed/meteor-collection2.git'
 });
@@ -23,7 +23,7 @@ Package.onUse(function (api) {
   api.use('ejson');
   api.use('ecmascript');
   api.use('raix:eventemitter@1.0.0');
-  api.use('aldeed:simple-schema@1.13.1 || 2.0.0-rc.300.10');
+  api.use('aldeed:simple-schema@1.13.1 || 2.0.0-rc300.1');
 
   api.addFiles(['./collection2.js']);