diff --git a/Source/Scene/PostProcessStageCollection.js b/Source/Scene/PostProcessStageCollection.js
index a7eba11beede..b23acfb816ae 100644
--- a/Source/Scene/PostProcessStageCollection.js
+++ b/Source/Scene/PostProcessStageCollection.js
@@ -498,8 +498,8 @@ define([
                     height : 256
                 },
                 sampler : new Sampler({
-                    wrapS : TextureWrap.CLAMP_TO_EDGE,
-                    wrapT : TextureWrap.CLAMP_TO_EDGE,
+                    wrapS : TextureWrap.REPEAT,
+                    wrapT : TextureWrap.REPEAT,
                     minificationFilter : TextureMinificationFilter.NEAREST,
                     magnificationFilter : TextureMagnificationFilter.NEAREST
                 })
diff --git a/Source/Shaders/PostProcessStages/AmbientOcclusionGenerate.glsl b/Source/Shaders/PostProcessStages/AmbientOcclusionGenerate.glsl
index 59d84f3477c5..4a579dfc1e2c 100644
--- a/Source/Shaders/PostProcessStages/AmbientOcclusionGenerate.glsl
+++ b/Source/Shaders/PostProcessStages/AmbientOcclusionGenerate.glsl
@@ -58,9 +58,7 @@ void main(void)
     float gapAngle = 90.0 * czm_radiansPerDegree;
 
     // RandomNoise
-    vec2 noiseMapSize = vec2(256.0, 256.0);
-    vec2 noiseScale = vec2(czm_viewport.z /  noiseMapSize.x, czm_viewport.w / noiseMapSize.y);
-    float randomVal = texture2D(randomTexture, v_textureCoordinates * noiseScale).x;
+    float randomVal = texture2D(randomTexture, v_textureCoordinates).x;
 
     float inverseViewportWidth = 1.0 / czm_viewport.z;
     float inverseViewportHeight = 1.0 / czm_viewport.w;