diff --git a/src/renderer/webgl/PipelineManager.js b/src/renderer/webgl/PipelineManager.js
index 33f11d084..35a27c544 100644
--- a/src/renderer/webgl/PipelineManager.js
+++ b/src/renderer/webgl/PipelineManager.js
@@ -394,6 +394,8 @@ var PipelineManager = new Class({
 
             //  Duplicate RT for alt swap frame
             targets.push(new RenderTarget(renderer, targetWidth, targetWidth));
+
+            this.maxDimension = targetWidth;
         }
 
         //  Full-screen RTs
@@ -401,8 +403,6 @@ var PipelineManager = new Class({
         targets.push(new RenderTarget(renderer, renderWidth, renderHeight, 1, 0, true, true));
         targets.push(new RenderTarget(renderer, renderWidth, renderHeight, 1, 0, true, true));
 
-        this.maxDimension = (qty - 1) * this.frameInc;
-
         //  Install each of the default pipelines
 
         var instance;