diff --git a/index.js b/index.js
index 5253eff..9680f3c 100644
--- a/index.js
+++ b/index.js
@@ -143,8 +143,8 @@ Thumbor.prototype = {
    * @param  {String} height
    */
   resize: function(width, height) {
-    this.width = width;
-    this.height = height;
+    this.width = width || '';
+    this.height = height || '';
     return this;
   },
 
@@ -160,8 +160,8 @@ Thumbor.prototype = {
    * @param  {String} height
    */
   fitIn: function(width, height) {
-    this.width = width;
-    this.height = height;
+    this.width = width || '';
+    this.height = height || '';
     this.fitInFlag = true;
     return this;
   },
@@ -184,7 +184,6 @@ Thumbor.prototype = {
    * @param  {String} halign 'left', 'center', 'right'
    */
   halign: function(halign) {
-    console.log('halign: ', halign);
     if (
       halign === this.LEFT ||
       halign === this.RIGHT ||
@@ -226,7 +225,9 @@ Thumbor.prototype = {
    * @param  {String} filterCall
    */
   filter: function(filterCall) {
-    this.filtersCalls.push(filterCall);
+    if(this.filtersCalls.indexOf(filterCall) == -1) {
+        this.filtersCalls.push(filterCall);
+    }
     return this;
   },
   /**
@@ -274,4 +275,4 @@ Thumbor.prototype = {
   }
 };
 
-module.exports = Thumbor;
\ No newline at end of file
+module.exports = Thumbor;