diff --git a/src/ol/render.js b/src/ol/render.js
index 67c4a695ef..b55141bd14 100644
--- a/src/ol/render.js
+++ b/src/ol/render.js
@@ -20,9 +20,6 @@ goog.require('ol.vec.Mat4');
  *     new ol.geom.Polygon([[[0, 0], [100, 100], [100, 0], [0, 0]]]));
  * ```
  *
- * Note that {@link ol.render.canvas.Immediate#drawAsync} and
- * {@link ol.render.canvas.Immediate#drawFeature} cannot be used.
- *
  * @param {CanvasRenderingContext2D} context Canvas context.
  * @param {olx.render.ToContextOptions=} opt_options Options.
  * @return {ol.render.canvas.Immediate} Canvas Immediate.
diff --git a/src/ol/render/vectorcontext.js b/src/ol/render/vectorcontext.js
index 0b9cb7f80a..0fcf9db4a9 100644
--- a/src/ol/render/vectorcontext.js
+++ b/src/ol/render/vectorcontext.js
@@ -12,13 +12,6 @@ ol.render.VectorContext = function() {
 };
 
 
-/**
- * @param {number} zIndex Z index.
- * @param {function(ol.render.VectorContext)} callback Callback.
- */
-ol.render.VectorContext.prototype.drawAsync = goog.abstractMethod;
-
-
 /**
  * Render a geometry.
  *
diff --git a/src/ol/render/webgl/webglimmediate.js b/src/ol/render/webgl/webglimmediate.js
index 01c783fe15..f112f71e36 100644
--- a/src/ol/render/webgl/webglimmediate.js
+++ b/src/ol/render/webgl/webglimmediate.js
@@ -1,6 +1,5 @@
 goog.provide('ol.render.webgl.Immediate');
 goog.require('goog.asserts');
-goog.require('ol.array');
 goog.require('ol.extent');
 goog.require('ol.geom.GeometryType');
 goog.require('ol.render.VectorContext');
@@ -64,52 +63,10 @@ ol.render.webgl.Immediate = function(context, center, resolution, rotation, size
    */
   this.imageStyle_ = null;
 
-  /**
-   * @private
-   * @type {!Object.<string,
-   *        Array.<function(ol.render.webgl.Immediate)>>}
-   */
-  this.callbacksByZIndex_ = {};
 };
 goog.inherits(ol.render.webgl.Immediate, ol.render.VectorContext);
 
 
-/**
- * FIXME: empty description for jsdoc
- */
-ol.render.webgl.Immediate.prototype.flush = function() {
-  /** @type {Array.<number>} */
-  var zs = Object.keys(this.callbacksByZIndex_).map(Number);
-  zs.sort(ol.array.numberSafeCompareFunction);
-  var i, ii, callbacks, j, jj;
-  for (i = 0, ii = zs.length; i < ii; ++i) {
-    callbacks = this.callbacksByZIndex_[zs[i].toString()];
-    for (j = 0, jj = callbacks.length; j < jj; ++j) {
-      callbacks[j](this);
-    }
-  }
-};
-
-
-/**
- * Register a function to be called for rendering at a given zIndex.  The
- * function will be called asynchronously.  The callback will receive a
- * reference to {@link ol.render.canvas.Immediate} context for drawing.
- * @param {number} zIndex Z index.
- * @param {function(ol.render.webgl.Immediate)} callback Callback.
- * @api
- */
-ol.render.webgl.Immediate.prototype.drawAsync = function(zIndex, callback) {
-  var zIndexKey = zIndex.toString();
-  var callbacks = this.callbacksByZIndex_[zIndexKey];
-  if (callbacks !== undefined) {
-    callbacks.push(callback);
-  } else {
-    this.callbacksByZIndex_[zIndexKey] = [callback];
-  }
-};
-
-
 /**
  * Set the rendering style.  Note that since this is an immediate rendering API,
  * any `zIndex` on the provided style will be ignored.
@@ -157,15 +114,9 @@ ol.render.webgl.Immediate.prototype.drawFeature = function(feature, style) {
       !ol.extent.intersects(this.extent_, geometry.getExtent())) {
     return;
   }
-  var zIndex = style.getZIndex();
-  if (zIndex === undefined) {
-    zIndex = 0;
-  }
-  this.drawAsync(zIndex, function(render) {
-    render.setStyle(style);
-    goog.asserts.assert(geometry, 'geometry must be truthy');
-    render.drawGeometry(geometry);
-  });
+  this.setStyle(style);
+  goog.asserts.assert(geometry, 'geometry must be truthy');
+  this.drawGeometry(geometry);
 };
 
 
diff --git a/src/ol/render/webgl/webglreplay.js b/src/ol/render/webgl/webglreplay.js
index 18580f518e..10d3e1d68c 100644
--- a/src/ol/render/webgl/webglreplay.js
+++ b/src/ol/render/webgl/webglreplay.js
@@ -245,12 +245,6 @@ ol.render.webgl.ImageReplay.prototype.getDeleteResourcesFunction = function(cont
 };
 
 
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawAsync = goog.abstractMethod;
-
-
 /**
  * @param {Array.<number>} flatCoordinates Flat coordinates.
  * @param {number} offset Offset.
diff --git a/src/ol/renderer/webgl/webglmaprenderer.js b/src/ol/renderer/webgl/webglmaprenderer.js
index 07f1de15a3..99d8b49d21 100644
--- a/src/ol/renderer/webgl/webglmaprenderer.js
+++ b/src/ol/renderer/webgl/webglmaprenderer.js
@@ -288,8 +288,6 @@ ol.renderer.webgl.Map.prototype.dispatchComposeEvent_ = function(type, frameStat
     var composeEvent = new ol.render.Event(type, map, vectorContext,
         frameState, null, context);
     map.dispatchEvent(composeEvent);
-
-    vectorContext.flush();
   }
 };