diff --git a/lib/musicbrainz.js b/lib/musicbrainz.js
index c255752..9bd4dde 100644
--- a/lib/musicbrainz.js
+++ b/lib/musicbrainz.js
@@ -548,8 +548,9 @@ var Resource = function (mbid) {
 		var self = this;
 		this._lookup(this.id, linkedEntities, force, function (err, resource) {
 			if ( !err ) { 
-				for (i in self) {
-					self[i] = resource[i];
+				for (var i = 0; i < Object.keys(self).length; i++) {
+					var key = Object.keys(self)[i];
+					self[key] = resource[key];
 				}
 			}
 
@@ -575,9 +576,10 @@ var Resource = function (mbid) {
 	};
 
 	this.readData = function (linkedEntities, data) {
-		for (var i in linkedEntities) {
-			if (typeof this._readDataFunctions[linkedEntities[i]] === 'function') {
-				this._readDataFunctions[linkedEntities[i]](data);
+		for(var l = 0; l < Object.keys(linkedEntities).length; l++){
+			var linkedEntity = Object.keys(linkedEntities)[l];
+			if (typeof this._readDataFunctions[linkedEntities[linkedEntity]] === 'function') {
+				this._readDataFunctions[linkedEntities[linkedEntity]](data);
 			}
 		}
 	};
@@ -836,7 +838,8 @@ mb.search = function(resource, query, filter, force, callback){
 		uri = mbBaseURI + resource + '?query=';
 
 	if(filter instanceof Object) {
-		for(var key in filter){
+		for(var k = 0; k < Object.keys(filter).length; k++){
+			var key = Object.keys(filter)[k];
 			filterArr.push(key + ':' + encodeURIComponent(filter[key]));
 		}
 		filterStr = filterArr.join( encodeURIComponent(' AND ') );