diff --git a/extensions/firefox/content/PdfStreamConverter.jsm b/extensions/firefox/content/PdfStreamConverter.jsm
index b331444ca..9e12f10f2 100644
--- a/extensions/firefox/content/PdfStreamConverter.jsm
+++ b/extensions/firefox/content/PdfStreamConverter.jsm
@@ -662,8 +662,8 @@ var RangedChromeActions = (function RangedChromeActionsClosure() {
     // If we are in range request mode, this means we manually issued xhr
     // requests, which we need to abort when we leave the page
     domWindow.addEventListener('unload', function unload(e) {
-      self.networkManager.abortAllRequests();
       domWindow.removeEventListener(e.type, unload);
+      self.abortLoading();
     });
   }
 
@@ -691,7 +691,7 @@ var RangedChromeActions = (function RangedChromeActionsClosure() {
         }, '*');
       };
       this.dataListener.oncomplete = function () {
-        delete self.dataListener;
+        self.dataListener = null;
       };
     }
 
@@ -735,6 +735,15 @@ var RangedChromeActions = (function RangedChromeActionsClosure() {
     });
   };
 
+  proto.abortLoading = function RangedChromeActions_abortLoading() {
+    this.networkManager.abortAllRequests();
+    if (this.originalRequest) {
+      this.originalRequest.cancel(Cr.NS_BINDING_ABORTED);
+      this.originalRequest = null;
+    }
+    this.dataListener = null;
+  };
+
   return RangedChromeActions;
 })();
 
@@ -744,9 +753,10 @@ var StandardChromeActions = (function StandardChromeActionsClosure() {
    * This is for a single network stream
    */
   function StandardChromeActions(domWindow, contentDispositionFilename,
-                                 dataListener) {
+                                 originalRequest, dataListener) {
 
     ChromeActions.call(this, domWindow, contentDispositionFilename);
+    this.originalRequest = originalRequest;
     this.dataListener = dataListener;
   }
 
@@ -772,20 +782,29 @@ var StandardChromeActions = (function StandardChromeActionsClosure() {
       }, '*');
     };
 
-    this.dataListener.oncomplete = function ChromeActions_dataListenerComplete(
-                                      data, errorCode) {
+    this.dataListener.oncomplete =
+        function StandardChromeActions_dataListenerComplete(data, errorCode) {
       self.domWindow.postMessage({
         pdfjsLoadAction: 'complete',
         data: data,
         errorCode: errorCode
       }, '*');
 
-      delete self.dataListener;
+      self.dataListener = null;
+      self.originalRequest = null;
     };
 
     return true;
   };
 
+  proto.abortLoading = function StandardChromeActions_abortLoading() {
+    if (this.originalRequest) {
+      this.originalRequest.cancel(Cr.NS_BINDING_ABORTED);
+      this.originalRequest = null;
+    }
+    this.dataListener = null;
+  };
+
   return StandardChromeActions;
 })();
 
@@ -1029,7 +1048,7 @@ PdfStreamConverter.prototype = {
             rangeRequest, streamRequest, dataListener);
         } else {
           actions = new StandardChromeActions(
-            domWindow, contentDispositionFilename, dataListener);
+            domWindow, contentDispositionFilename, aRequest, dataListener);
         }
         var requestListener = new RequestListener(actions);
         domWindow.addEventListener(PDFJS_EVENT_ID, function(event) {
diff --git a/src/core/chunked_stream.js b/src/core/chunked_stream.js
index b0a7b46fe..de20ba101 100644
--- a/src/core/chunked_stream.js
+++ b/src/core/chunked_stream.js
@@ -301,7 +301,7 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
 
     this.chunksNeededByRequest = {};
     this.requestsByChunk = {};
-    this.callbacksByRequest = {};
+    this.promisesByRequest = {};
     this.progressiveDataLength = 0;
 
     this._loadedStreamCapability = createPromiseCapability();
@@ -320,12 +320,11 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
     // contiguous ranges to load in as few requests as possible
     requestAllChunks: function ChunkedStreamManager_requestAllChunks() {
       var missingChunks = this.stream.getMissingChunks();
-      this.requestChunks(missingChunks);
+      this._requestChunks(missingChunks);
       return this._loadedStreamCapability.promise;
     },
 
-    requestChunks: function ChunkedStreamManager_requestChunks(chunks,
-                                                               callback) {
+    _requestChunks: function ChunkedStreamManager_requestChunks(chunks) {
       var requestId = this.currRequestId++;
 
       var chunksNeeded;
@@ -338,13 +337,11 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
       }
 
       if (isEmptyObj(chunksNeeded)) {
-        if (callback) {
-          callback();
-        }
-        return;
+        return Promise.resolve();
       }
 
-      this.callbacksByRequest[requestId] = callback;
+      var capability = createPromiseCapability();
+      this.promisesByRequest[requestId] = capability;
 
       var chunksToRequest = [];
       for (var chunk in chunksNeeded) {
@@ -357,7 +354,7 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
       }
 
       if (!chunksToRequest.length) {
-        return;
+        return capability.promise;
       }
 
       var groupedChunksToRequest = this.groupChunks(chunksToRequest);
@@ -368,6 +365,8 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
         var end = Math.min(groupedChunk.endChunk * this.chunkSize, this.length);
         this.sendRequest(begin, end);
       }
+
+      return capability.promise;
     },
 
     getStream: function ChunkedStreamManager_getStream() {
@@ -375,8 +374,7 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
     },
 
     // Loads any chunks in the requested range that are not yet loaded
-    requestRange: function ChunkedStreamManager_requestRange(
-                      begin, end, callback) {
+    requestRange: function ChunkedStreamManager_requestRange(begin, end) {
 
       end = Math.min(end, this.length);
 
@@ -388,11 +386,10 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
         chunks.push(chunk);
       }
 
-      this.requestChunks(chunks, callback);
+      return this._requestChunks(chunks);
     },
 
-    requestRanges: function ChunkedStreamManager_requestRanges(ranges,
-                                                               callback) {
+    requestRanges: function ChunkedStreamManager_requestRanges(ranges) {
       ranges = ranges || [];
       var chunksToRequest = [];
 
@@ -407,7 +404,7 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
       }
 
       chunksToRequest.sort(function(a, b) { return a - b; });
-      this.requestChunks(chunksToRequest, callback);
+      return this._requestChunks(chunksToRequest);
     },
 
     // Groups a sorted array of chunks into as few contiguous larger
@@ -506,17 +503,15 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
           nextEmptyChunk = this.stream.nextEmptyChunk(endChunk);
         }
         if (isInt(nextEmptyChunk)) {
-          this.requestChunks([nextEmptyChunk]);
+          this._requestChunks([nextEmptyChunk]);
         }
       }
 
       for (i = 0; i < loadedRequests.length; ++i) {
         requestId = loadedRequests[i];
-        var callback = this.callbacksByRequest[requestId];
-        delete this.callbacksByRequest[requestId];
-        if (callback) {
-          callback();
-        }
+        var capability = this.promisesByRequest[requestId];
+        delete this.promisesByRequest[requestId];
+        capability.resolve();
       }
 
       this.msgHandler.send('DocProgress', {
@@ -537,6 +532,16 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
     getEndChunk: function ChunkedStreamManager_getEndChunk(end) {
       var chunk = Math.floor((end - 1) / this.chunkSize) + 1;
       return chunk;
+    },
+
+    abort: function ChunkedStreamManager_abort() {
+      if (this.networkManager) {
+        this.networkManager.abortAllRequests();
+      }
+      for(var requestId in this.promisesByRequest) {
+        var capability = this.promisesByRequest[requestId];
+        capability.reject(new Error('Request was aborted'));
+      }
     }
   };
 
diff --git a/src/core/obj.js b/src/core/obj.js
index fe5135fc5..ef8766e46 100644
--- a/src/core/obj.js
+++ b/src/core/obj.js
@@ -1378,9 +1378,9 @@ var XRef = (function XRefClosure() {
           resolve(xref.fetch(ref, suppressEncryption));
         } catch (e) {
           if (e instanceof MissingDataException) {
-            streamManager.requestRange(e.begin, e.end, function () {
+            streamManager.requestRange(e.begin, e.end).then(function () {
               tryFetch(resolve, reject);
-            });
+            }, reject);
             return;
           }
           reject(e);
@@ -1656,6 +1656,7 @@ var ObjectLoader = (function() {
     this.keys = keys;
     this.xref = xref;
     this.refSet = null;
+    this.capability = null;
   }
 
   ObjectLoader.prototype = {
@@ -1676,11 +1677,11 @@ var ObjectLoader = (function() {
         nodesToVisit.push(this.obj[keys[i]]);
       }
 
-      this.walk(nodesToVisit);
+      this._walk(nodesToVisit);
       return this.capability.promise;
     },
 
-    walk: function ObjectLoader_walk(nodesToVisit) {
+    _walk: function ObjectLoader_walk(nodesToVisit) {
       var nodesToRevisit = [];
       var pendingRequests = [];
       // DFS walk of the object graph.
@@ -1727,7 +1728,7 @@ var ObjectLoader = (function() {
       }
 
       if (pendingRequests.length) {
-        this.xref.stream.manager.requestRanges(pendingRequests,
+        this.xref.stream.manager.requestRanges(pendingRequests).then(
             function pendingRequestCallback() {
           nodesToVisit = nodesToRevisit;
           for (var i = 0; i < nodesToRevisit.length; i++) {
@@ -1738,8 +1739,8 @@ var ObjectLoader = (function() {
               this.refSet.remove(node);
             }
           }
-          this.walk(nodesToVisit);
-        }.bind(this));
+          this._walk(nodesToVisit);
+        }.bind(this), this.capability.reject);
         return;
       }
       // Everything is loaded.
diff --git a/src/core/pdf_manager.js b/src/core/pdf_manager.js
index 3101e4edf..b264fdef9 100644
--- a/src/core/pdf_manager.js
+++ b/src/core/pdf_manager.js
@@ -183,7 +183,8 @@ var NetworkPdfManager = (function NetworkPdfManagerClosure() {
             reject(e);
             return;
           }
-          pdfManager.streamManager.requestRange(e.begin, e.end, ensureHelper);
+          pdfManager.streamManager.requestRange(e.begin, e.end).
+            then(ensureHelper, reject);
         }
       }
 
@@ -193,11 +194,7 @@ var NetworkPdfManager = (function NetworkPdfManagerClosure() {
 
   NetworkPdfManager.prototype.requestRange =
       function NetworkPdfManager_requestRange(begin, end) {
-    return new Promise(function (resolve) {
-      this.streamManager.requestRange(begin, end, function() {
-        resolve();
-      });
-    }.bind(this));
+    return this.streamManager.requestRange(begin, end);
   };
 
   NetworkPdfManager.prototype.requestLoadedStream =
@@ -217,7 +214,7 @@ var NetworkPdfManager = (function NetworkPdfManagerClosure() {
 
   NetworkPdfManager.prototype.terminate =
       function NetworkPdfManager_terminate() {
-    this.streamManager.networkManager.abortAllRequests();
+    this.streamManager.abort();
   };
 
   return NetworkPdfManager;
diff --git a/src/core/worker.js b/src/core/worker.js
index 40d7d899e..9fc3ea440 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -25,6 +25,14 @@
 var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
   setup: function wphSetup(handler) {
     var pdfManager;
+    var terminated = false;
+    var cancelXHRs = null;
+
+    function ensureNotTerminated() {
+      if (terminated) {
+        throw new Error('Worker was terminated');
+      }
+    }
 
     function loadDocument(recoveryMode) {
       var loadDocumentCapability = createPromiseCapability();
@@ -61,13 +69,14 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
 
     function getPdfManager(data) {
       var pdfManagerCapability = createPromiseCapability();
+      var pdfManager;
 
       var source = data.source;
       var disableRange = data.disableRange;
       if (source.data) {
         try {
           pdfManager = new LocalPdfManager(source.data, source.password);
-          pdfManagerCapability.resolve();
+          pdfManagerCapability.resolve(pdfManager);
         } catch (ex) {
           pdfManagerCapability.reject(ex);
         }
@@ -75,7 +84,7 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
       } else if (source.chunkedViewerLoading) {
         try {
           pdfManager = new NetworkPdfManager(source, handler);
-          pdfManagerCapability.resolve();
+          pdfManagerCapability.resolve(pdfManager);
         } catch (ex) {
           pdfManagerCapability.reject(ex);
         }
@@ -136,6 +145,7 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
           } catch (ex) {
             pdfManagerCapability.reject(ex);
           }
+          cancelXHRs = null;
         },
 
         onProgressiveData: source.disableStream ? null :
@@ -176,10 +186,11 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
           // the data is array, instantiating directly from it
           try {
             pdfManager = new LocalPdfManager(pdfFile, source.password);
-            pdfManagerCapability.resolve();
+            pdfManagerCapability.resolve(pdfManager);
           } catch (ex) {
             pdfManagerCapability.reject(ex);
           }
+          cancelXHRs = null;
         },
 
         onError: function onError(status) {
@@ -194,6 +205,7 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
               ') while retrieving PDF "' + source.url + '".', status);
             handler.send('UnexpectedResponse', exception);
           }
+          cancelXHRs = null;
         },
 
         onProgress: function onProgress(evt) {
@@ -204,6 +216,10 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
         }
       });
 
+      cancelXHRs = function () {
+        networkManager.abortRequest(fullRequestXhrId);
+      };
+
       return pdfManagerCapability.promise;
     }
 
@@ -236,8 +252,8 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
     });
 
     handler.on('GetDocRequest', function wphSetupDoc(data) {
-
       var onSuccess = function(doc) {
+        ensureNotTerminated();
         handler.send('GetDoc', { pdfInfo: doc });
       };
 
@@ -260,6 +276,8 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
         }
       };
 
+      ensureNotTerminated();
+
       PDFJS.maxImageSize = data.maxImageSize === undefined ?
                            -1 : data.maxImageSize;
       PDFJS.disableFontFace = data.disableFontFace;
@@ -269,13 +287,26 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
                            null : data.cMapUrl;
       PDFJS.cMapPacked = data.cMapPacked === true;
 
-      getPdfManager(data).then(function () {
+      getPdfManager(data).then(function (newPdfManager) {
+        if (terminated) {
+          // We were in a process of setting up the manager, but it got
+          // terminated in the middle.
+          newPdfManager.terminate();
+          throw new Error('Worker was terminated');
+        }
+
+        pdfManager = newPdfManager;
+
         handler.send('PDFManagerReady', null);
         pdfManager.onLoadedStream().then(function(stream) {
           handler.send('DataLoaded', { length: stream.bytes.byteLength });
         });
       }).then(function pdfManagerReady() {
+        ensureNotTerminated();
+
         loadDocument(false).then(onSuccess, function loadFailure(ex) {
+          ensureNotTerminated();
+
           // Try again with recoveryMode == true
           if (!(ex instanceof XRefParseException)) {
             if (ex instanceof PasswordException) {
@@ -290,6 +321,8 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
 
           pdfManager.requestLoadedStream();
           pdfManager.onLoadedStream().then(function() {
+            ensureNotTerminated();
+
             loadDocument(true).then(onSuccess, onFailure);
           });
         }, onFailure);
@@ -441,7 +474,14 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
     });
 
     handler.on('Terminate', function wphTerminate(data) {
-      pdfManager.terminate();
+      terminated = true;
+      if (pdfManager) {
+        pdfManager.terminate();
+        pdfManager = null;
+      }
+      if (cancelXHRs) {
+        cancelXHRs();
+      }
     });
   }
 };
diff --git a/src/display/api.js b/src/display/api.js
index c89c931a8..08b02caf1 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -265,6 +265,9 @@ PDFJS.getDocument = function getDocument(src,
       pdfDataRangeTransport = Object.create(pdfDataRangeTransport);
       pdfDataRangeTransport.length = src.length;
       pdfDataRangeTransport.initialData = src.initialData;
+      if (!pdfDataRangeTransport.abort) {
+        pdfDataRangeTransport.abort = function () {};
+      }
     }
     src = Object.create(src);
     src.range = pdfDataRangeTransport;
@@ -324,6 +327,7 @@ PDFJS.getDocument = function getDocument(src,
   workerInitializedCapability.promise.then(function transportInitialized() {
     transport.fetchDocument(task, params);
   });
+  task._transport = transport;
 
   return task;
 };
@@ -336,6 +340,7 @@ var PDFDocumentLoadingTask = (function PDFDocumentLoadingTaskClosure() {
   /** @constructs PDFDocumentLoadingTask */
   function PDFDocumentLoadingTask() {
     this._capability = createPromiseCapability();
+    this._transport = null;
 
     /**
      * Callback to request a password if wrong or no password was provided.
@@ -361,7 +366,14 @@ var PDFDocumentLoadingTask = (function PDFDocumentLoadingTaskClosure() {
       return this._capability.promise;
     },
 
-    // TODO add cancel or abort method
+    /**
+     * Aborts all network requests and destroys worker.
+     * @return {Promise} A promise that is resolved after destruction activity
+     *                   is completed.
+     */
+    destroy: function () {
+      return this._transport.destroy();
+    },
 
     /**
      * Registers callbacks to indicate the document loading completion.
@@ -448,6 +460,9 @@ var PDFDataRangeTransport = (function pdfDataRangeTransportClosure() {
     requestDataRange:
         function PDFDataRangeTransport_requestDataRange(begin, end) {
       throw new Error('Abstract method PDFDataRangeTransport.requestDataRange');
+    },
+
+    abort: function PDFDataRangeTransport_abort() {
     }
   };
   return PDFDataRangeTransport;
@@ -461,9 +476,10 @@ PDFJS.PDFDataRangeTransport = PDFDataRangeTransport;
  * @class
  */
 var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
-  function PDFDocumentProxy(pdfInfo, transport) {
+  function PDFDocumentProxy(pdfInfo, transport, loadingTask) {
     this.pdfInfo = pdfInfo;
     this.transport = transport;
+    this.loadingTask = loadingTask;
   }
   PDFDocumentProxy.prototype = /** @lends PDFDocumentProxy.prototype */ {
     /**
@@ -586,7 +602,7 @@ var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
      * Destroys current document instance and terminates worker.
      */
     destroy: function PDFDocumentProxy_destroy() {
-      this.transport.destroy();
+      return this.transport.destroy();
     }
   };
   return PDFDocumentProxy;
@@ -663,8 +679,9 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
     this.commonObjs = transport.commonObjs;
     this.objs = new PDFObjects();
     this.cleanupAfterRender = false;
-    this.pendingDestroy = false;
+    this.pendingCleanup = false;
     this.intentStates = {};
+    this.destroyed = false;
   }
   PDFPageProxy.prototype = /** @lends PDFPageProxy.prototype */ {
     /**
@@ -728,7 +745,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
 
       // If there was a pending destroy cancel it so no cleanup happens during
       // this call to render.
-      this.pendingDestroy = false;
+      this.pendingCleanup = false;
 
       var renderingIntent = (params.intent === 'print' ? 'print' : 'display');
 
@@ -775,7 +792,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
       var self = this;
       intentState.displayReadyCapability.promise.then(
         function pageDisplayReadyPromise(transparency) {
-          if (self.pendingDestroy) {
+          if (self.pendingCleanup) {
             complete();
             return;
           }
@@ -795,9 +812,9 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
         }
 
         if (self.cleanupAfterRender) {
-          self.pendingDestroy = true;
+          self.pendingCleanup = true;
         }
-        self._tryDestroy();
+        self._tryCleanup();
 
         if (error) {
           internalRenderTask.capability.reject(error);
@@ -858,20 +875,47 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
         pageIndex: this.pageNumber - 1
       });
     },
+
     /**
-     * Destroys resources allocated by the page.
+     * Destroys page object.
      */
-    destroy: function PDFPageProxy_destroy() {
-      this.pendingDestroy = true;
-      this._tryDestroy();
+    _destroy: function PDFPageProxy_destroy() {
+      this.destroyed = true;
+      this.transport.pageCache[this.pageIndex] = null;
+
+      Object.keys(this.intentStates).forEach(function(intent) {
+        var intentState = this.intentStates[intent];
+        intentState.renderTasks.forEach(function(renderTask) {
+          renderTask.cancel();
+        });
+      }, this);
+      this.objs.clear();
+      this.annotationsPromise = null;
+      this.pendingCleanup = false;
+    },
+
+    /**
+     * Cleans up resources allocated by the page.
+     * Deprecated, use cleanup() instead.
+     */
+    destroy: function() {
+      this.cleanup();
+    },
+
+    /**
+     * Cleans up resources allocated by the page.
+     */
+    cleanup: function PDFPageProxy_cleanup() {
+      this.pendingCleanup = true;
+      this._tryCleanup();
     },
     /**
      * For internal use only. Attempts to clean up if rendering is in a state
      * where that's possible.
      * @ignore
      */
-    _tryDestroy: function PDFPageProxy__destroy() {
-      if (!this.pendingDestroy ||
+    _tryCleanup: function PDFPageProxy_tryCleanup() {
+      if (!this.pendingCleanup ||
           Object.keys(this.intentStates).some(function(intent) {
             var intentState = this.intentStates[intent];
             return (intentState.renderTasks.length !== 0 ||
@@ -885,7 +929,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
       }, this);
       this.objs.clear();
       this.annotationsPromise = null;
-      this.pendingDestroy = false;
+      this.pendingCleanup = false;
     },
     /**
      * For internal use only.
@@ -923,7 +967,7 @@ var PDFPageProxy = (function PDFPageProxyClosure() {
 
       if (operatorListChunk.lastChunk) {
         intentState.receivingOperatorList = false;
-        this._tryDestroy();
+        this._tryCleanup();
       }
     }
   };
@@ -941,6 +985,8 @@ var WorkerTransport = (function WorkerTransportClosure() {
     this.commonObjs = new PDFObjects();
 
     this.loadingTask = null;
+    this.destroyed = false;
+    this.destroyCapability = null;
 
     this.pageCache = [];
     this.pagePromises = [];
@@ -1001,6 +1047,18 @@ var WorkerTransport = (function WorkerTransportClosure() {
   }
   WorkerTransport.prototype = {
     destroy: function WorkerTransport_destroy() {
+      if (this.destroyCapability) {
+        return this.destroyCapability.promise;
+      }
+
+      this.destroyed = true;
+      this.destroyCapability = createPromiseCapability();
+
+      this.pageCache.forEach(function (page) {
+        if (page) {
+          page._destroy();
+        }
+      });
       this.pageCache = [];
       this.pagePromises = [];
       var self = this;
@@ -1009,7 +1067,14 @@ var WorkerTransport = (function WorkerTransportClosure() {
         if (self.worker) {
           self.worker.terminate();
         }
-      });
+        if (self.pdfDataRangeTransport) {
+          self.pdfDataRangeTransport.abort();
+          self.pdfDataRangeTransport = null;
+        }
+        self.messageHandler = null;
+        self.destroyCapability.resolve();
+      }, this.destroyCapability.reject);
+      return this.destroyCapability.promise;
     },
 
     setupFakeWorker: function WorkerTransport_setupFakeWorker() {
@@ -1091,9 +1156,10 @@ var WorkerTransport = (function WorkerTransportClosure() {
       messageHandler.on('GetDoc', function transportDoc(data) {
         var pdfInfo = data.pdfInfo;
         this.numPages = data.pdfInfo.numPages;
-        var pdfDocument = new PDFDocumentProxy(pdfInfo, this);
+        var loadingTask = this.loadingTask;
+        var pdfDocument = new PDFDocumentProxy(pdfInfo, this, loadingTask);
         this.pdfDocument = pdfDocument;
-        this.loadingTask._capability.resolve(pdfDocument);
+        loadingTask._capability.resolve(pdfDocument);
       }, this);
 
       messageHandler.on('NeedPassword',
@@ -1294,6 +1360,12 @@ var WorkerTransport = (function WorkerTransportClosure() {
     },
 
     fetchDocument: function WorkerTransport_fetchDocument(loadingTask, source) {
+      if (this.destroyed) {
+        loadingTask._capability.reject(new Error('Loading aborted'));
+        this.destroyCapability.resolve();
+        return;
+      }
+
       this.loadingTask = loadingTask;
 
       source.disableAutoFetch = PDFJS.disableAutoFetch;
@@ -1332,6 +1404,9 @@ var WorkerTransport = (function WorkerTransportClosure() {
       var promise = this.messageHandler.sendWithPromise('GetPage', {
         pageIndex: pageIndex
       }).then(function (pageInfo) {
+        if (this.destroyed) {
+          throw new Error('Transport destroyed');
+        }
         var page = new PDFPageProxy(pageIndex, pageInfo, this);
         this.pageCache[pageIndex] = page;
         return page;
@@ -1389,7 +1464,7 @@ var WorkerTransport = (function WorkerTransportClosure() {
         for (var i = 0, ii = this.pageCache.length; i < ii; i++) {
           var page = this.pageCache[i];
           if (page) {
-            page.destroy();
+            page.cleanup();
           }
         }
         this.commonObjs.clear();
diff --git a/test/unit/api_spec.js b/test/unit/api_spec.js
index b183b9793..36f97ab4e 100644
--- a/test/unit/api_spec.js
+++ b/test/unit/api_spec.js
@@ -11,31 +11,31 @@ describe('api', function() {
   var basicApiUrl = combineUrl(window.location.href, '../pdfs/basicapi.pdf');
   var basicApiFileLength = 105779; // bytes
   function waitsForPromiseResolved(promise, successCallback) {
-    var data;
+    var resolved = false;
     promise.then(function(val) {
-      data = val;
-      successCallback(data);
+      resolved = true;
+      successCallback(val);
     },
     function(error) {
       // Shouldn't get here.
       expect(false).toEqual(true);
     });
     waitsFor(function() {
-      return data !== undefined;
+      return resolved;
     }, 20000);
   }
   function waitsForPromiseRejected(promise, failureCallback) {
-    var data;
+    var rejected = false;
     promise.then(function(val) {
       // Shouldn't get here.
       expect(false).toEqual(true);
     },
     function(error) {
-      data = error;
-      failureCallback(data);
+      rejected = true;
+      failureCallback(error);
     });
     waitsFor(function() {
-      return data !== undefined;
+      return rejected;
     }, 20000);
   }
 
@@ -63,6 +63,28 @@ describe('api', function() {
         waitsForPromiseResolved(Promise.all(promises), function (data) {
           expect((data[0].loaded / data[0].total) > 0).toEqual(true);
           expect(data[1] instanceof PDFDocumentProxy).toEqual(true);
+          expect(loadingTask).toEqual(data[1].loadingTask);
+        });
+      });
+      it('creates pdf doc from URL and aborts before worker initialized',
+          function() {
+        var loadingTask = PDFJS.getDocument(basicApiUrl);
+        loadingTask.destroy();
+        waitsForPromiseRejected(loadingTask.promise, function(reason) {
+          expect(true).toEqual(true);
+        });
+      });
+      it('creates pdf doc from URL and aborts loading after worker initialized',
+          function() {
+        var loadingTask = PDFJS.getDocument(basicApiUrl);
+        // This can be somewhat random -- we cannot guarantee perfect
+        // 'Terminate' message to the worker before/after setting up pdfManager.
+        var destroyed = loadingTask._transport.workerInitializedCapability.
+          promise.then(function () {
+          return loadingTask.destroy();
+        });
+        waitsForPromiseResolved(destroyed, function (data) {
+          expect(true).toEqual(true);
         });
       });
       it('creates pdf doc from typed array', function() {
diff --git a/test/unit/unit_test.html b/test/unit/unit_test.html
index 9193dbcd7..5fe1f254b 100644
--- a/test/unit/unit_test.html
+++ b/test/unit/unit_test.html
@@ -35,6 +35,7 @@
   <script src="../../src/core/parser.js"></script>
   <script src="../../src/core/ps_parser.js"></script>
   <script src="../../src/display/pattern_helper.js"></script>
+  <script src="../../src/display/font_loader.js"></script>
   <script src="../../src/display/annotation_helper.js"></script>
   <script src="../../src/core/stream.js"></script>
   <script src="../../src/core/worker.js"></script>
diff --git a/web/pdf_page_view.js b/web/pdf_page_view.js
index bec6d1d95..d3f2d9ace 100644
--- a/web/pdf_page_view.js
+++ b/web/pdf_page_view.js
@@ -101,7 +101,7 @@ var PDFPageView = (function PDFPageViewClosure() {
       this.zoomLayer = null;
       this.reset();
       if (this.pdfPage) {
-        this.pdfPage.destroy();
+        this.pdfPage.cleanup();
       }
     },
 
diff --git a/web/viewer.js b/web/viewer.js
index 4b25ffe3c..bb53afa2e 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -410,6 +410,11 @@ var PDFViewerApplication = {
         function FirefoxComDataRangeTransport_requestDataRange(begin, end) {
       FirefoxCom.request('requestDataRange', { begin: begin, end: end });
     };
+    FirefoxComDataRangeTransport.prototype.abort =
+        function FirefoxComDataRangeTransport_abort() {
+      // Sync call to ensure abort is really started.
+      FirefoxCom.requestSync('abortLoading', null);
+    };
 
     var pdfDataRangeTransport;