diff --git a/src/ol/renderer/webgl/webglmaprenderer.js b/src/ol/renderer/webgl/webglmaprenderer.js
index 52a025120a..e6f491079c 100644
--- a/src/ol/renderer/webgl/webglmaprenderer.js
+++ b/src/ol/renderer/webgl/webglmaprenderer.js
@@ -521,7 +521,7 @@ ol.renderer.webgl.Map.prototype.renderFrame = function(frameState) {
 
   this.focus_ = frameState.focus;
 
-  this.textureCache_.set(frameState.index.toString(), null);
+  this.textureCache_.set((-frameState.index).toString(), null);
   ++this.textureCacheFrameMarkerCount_;
 
   var layerStates = frameState.layerStates;