diff --git a/src/filters/base_filter.class.js b/src/filters/base_filter.class.js
index 8547a2cd438..323b2564e40 100644
--- a/src/filters/base_filter.class.js
+++ b/src/filters/base_filter.class.js
@@ -102,8 +102,8 @@ fabric.Image.filters.BaseFilter = fabric.util.createClass(/** @lends fabric.Imag
 
     var attributeLocations = this.getAttributeLocations(gl, program);
     var uniformLocations = this.getUniformLocations(gl, program) || { };
-    uniformLocations.uWidth = gl.getUniformLocation(program, 'uWidth');
-    uniformLocations.uHeight = gl.getUniformLocation(program, 'uHeight');
+    uniformLocations.uStepW = gl.getUniformLocation(program, 'uStepW');
+    uniformLocations.uStepH = gl.getUniformLocation(program, 'uStepH');
     return {
       program: program,
       attributeLocations: attributeLocations,
diff --git a/src/filters/pixelate_filter.class.js b/src/filters/pixelate_filter.class.js
index 4a27048c29c..5a14b966c61 100644
--- a/src/filters/pixelate_filter.class.js
+++ b/src/filters/pixelate_filter.class.js
@@ -105,8 +105,8 @@
     getUniformLocations: function(gl, program) {
       return {
         uBlocksize: gl.getUniformLocation(program, 'uBlocksize'),
-        uWidth: gl.getUniformLocation(program, 'uWidth'),
-        uHeight: gl.getUniformLocation(program, 'uHeight'),
+        uStepW: gl.getUniformLocation(program, 'uStepW'),
+        uStepH: gl.getUniformLocation(program, 'uStepH'),
       };
     },