diff --git a/src/core/annotation.js b/src/core/annotation.js
index 75d030535..c198374f3 100644
--- a/src/core/annotation.js
+++ b/src/core/annotation.js
@@ -65,18 +65,15 @@ AnnotationFactory.prototype = /** @lends AnnotationFactory.prototype */ {
    * @param {XRef} xref
    * @param {Object} ref
    * @param {PDFManager} pdfManager
-   * @param {string} uniquePrefix
-   * @param {Object} idCounters
+   * @param {Object} idFactory
    * @returns {Annotation}
    */
-  create: function AnnotationFactory_create(xref, ref, pdfManager,
-                                            uniquePrefix, idCounters) {
+  create: function AnnotationFactory_create(xref, ref, pdfManager, idFactory) {
     var dict = xref.fetchIfRef(ref);
     if (!isDict(dict)) {
       return;
     }
-    var id = isRef(ref) ? ref.toString() :
-                          'annot_' + (uniquePrefix || '') + (++idCounters.obj);
+    var id = isRef(ref) ? ref.toString() : 'annot_' + idFactory.createObjId();
 
     // Determine the annotation's subtype.
     var subtype = dict.get('Subtype');
diff --git a/src/core/document.js b/src/core/document.js
index df8268fdf..9b2e4eade 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -78,12 +78,18 @@ var Page = (function PageClosure() {
     this.xref = xref;
     this.ref = ref;
     this.fontCache = fontCache;
-    this.uniquePrefix = 'p' + this.pageIndex + '_';
-    this.idCounters = {
-      obj: 0
-    };
     this.evaluatorOptions = pdfManager.evaluatorOptions;
     this.resourcesPromise = null;
+
+    var uniquePrefix = 'p' + this.pageIndex + '_';
+    var idCounters = {
+      obj: 0,
+    };
+    this.idFactory = {
+      createObjId: function () {
+        return uniquePrefix + (++idCounters.obj);
+      },
+    };
   }
 
   Page.prototype = {
@@ -240,8 +246,7 @@ var Page = (function PageClosure() {
 
       var partialEvaluator = new PartialEvaluator(pdfManager, this.xref,
                                                   handler, this.pageIndex,
-                                                  this.uniquePrefix,
-                                                  this.idCounters,
+                                                  this.idFactory,
                                                   this.fontCache,
                                                   this.evaluatorOptions);
 
@@ -308,8 +313,7 @@ var Page = (function PageClosure() {
         var contentStream = data[0];
         var partialEvaluator = new PartialEvaluator(pdfManager, self.xref,
                                                     handler, self.pageIndex,
-                                                    self.uniquePrefix,
-                                                    self.idCounters,
+                                                    self.idFactory,
                                                     self.fontCache,
                                                     self.evaluatorOptions);
 
@@ -345,8 +349,7 @@ var Page = (function PageClosure() {
         var annotationRef = annotationRefs[i];
         var annotation = annotationFactory.create(this.xref, annotationRef,
                                                   this.pdfManager,
-                                                  this.uniquePrefix,
-                                                  this.idCounters);
+                                                  this.idFactory);
         if (annotation) {
           annotations.push(annotation);
         }
diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 74ab517a3..ead82fbf8 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -169,13 +169,12 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
   };
 
   function PartialEvaluator(pdfManager, xref, handler, pageIndex,
-                            uniquePrefix, idCounters, fontCache, options) {
+                            idFactory, fontCache, options) {
     this.pdfManager = pdfManager;
     this.xref = xref;
     this.handler = handler;
     this.pageIndex = pageIndex;
-    this.uniquePrefix = uniquePrefix;
-    this.idCounters = idCounters;
+    this.idFactory = idFactory;
     this.fontCache = fontCache;
     this.options = options || DefaultPartialEvaluatorOptions;
   }
@@ -391,8 +390,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
 
       // If there is no imageMask, create the PDFImage and a lot
       // of image processing can be done here.
-      var uniquePrefix = (this.uniquePrefix || '');
-      var objId = 'img_' + uniquePrefix + (++this.idCounters.obj);
+      var objId = 'img_' + this.idFactory.createObjId();
       operatorList.addDependency(objId);
       args = [objId, w, h];
 
@@ -733,7 +731,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
         this.fontCache.put(fontRef, fontCapability.promise);
       } else {
         if (!fontID) {
-          fontID = (this.uniquePrefix || 'F_') + (++this.idCounters.obj);
+          fontID = this.idFactory.createObjId();
         }
         this.fontCache.put('id_' + fontID, fontCapability.promise);
       }
diff --git a/test/unit/annotation_layer_spec.js b/test/unit/annotation_layer_spec.js
index a7be57244..aeb33dafd 100644
--- a/test/unit/annotation_layer_spec.js
+++ b/test/unit/annotation_layer_spec.js
@@ -17,21 +17,19 @@
 (function (root, factory) {
   if (typeof define === 'function' && define.amd) {
     define('pdfjs-test/unit/annotation_layer_spec', ['exports',
-           'pdfjs/core/primitives', 'pdfjs/core/annotation',
-           'pdfjs/core/stream', 'pdfjs/core/parser',
-           'pdfjs/shared/util', 'pdfjs/display/global'], factory);
+      'pdfjs/core/primitives', 'pdfjs/core/annotation', 'pdfjs/core/stream',
+      'pdfjs/core/parser', 'pdfjs/shared/util', 'pdfjs/display/global'],
+      factory);
   } else if (typeof exports !== 'undefined') {
     factory(exports, require('../../src/core/primitives.js'),
-            require('../../src/core/annotation.js'),
-            require('../../src/core/stream.js'),
-            require('../../src/core/parser.js'),
-            require('../../src/shared/util.js'),
-            require('../../src/display/global.js'));
+      require('../../src/core/annotation.js'),
+      require('../../src/core/stream.js'), require('../../src/core/parser.js'),
+      require('../../src/shared/util.js'),
+      require('../../src/display/global.js'));
   } else {
     factory((root.pdfjsTestUnitAnnotationLayerSpec = {}),
-             root.pdfjsCorePrimitives, root.pdfjsCoreAnnotation,
-             root.pdfjsCoreStream, root.pdfjsCoreParser,
-             root.pdfjsSharedUtil, root.pdfjsDisplayGlobal);
+      root.pdfjsCorePrimitives, root.pdfjsCoreAnnotation, root.pdfjsCoreStream,
+      root.pdfjsCoreParser, root.pdfjsSharedUtil, root.pdfjsDisplayGlobal);
   }
 }(this, function (exports, corePrimitives, coreAnnotation, coreStream,
                   coreParser, sharedUtil, displayGlobal) {
@@ -80,19 +78,34 @@ describe('Annotation layer', function() {
   }
   PDFManagerMock.prototype = {};
 
-  var annotationFactory, pdfManagerMock;
+  function IdFactoryMock(params) {
+    var uniquePrefix = params.prefix || 'p0_';
+    var idCounters = {
+      obj: params.startObjId || 0,
+    };
+    return {
+      createObjId: function () {
+        return uniquePrefix + (++idCounters.obj);
+      },
+    };
+  }
+  IdFactoryMock.prototype = {};
+
+  var annotationFactory, pdfManagerMock, idFactoryMock;
 
   beforeAll(function (done) {
     annotationFactory = new AnnotationFactory();
     pdfManagerMock = new PDFManagerMock({
       docBaseUrl: null,
     });
+    idFactoryMock = new IdFactoryMock({ });
     done();
   });
 
   afterAll(function () {
     annotationFactory = null;
     pdfManagerMock = null;
+    idFactoryMock = null;
   });
 
   describe('AnnotationFactory', function () {
@@ -107,7 +120,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -121,14 +134,15 @@ describe('Annotation layer', function() {
       annotationDict.set('Subtype', Name.get('Link'));
 
       var xref = new XRefMock();
-      var uniquePrefix = 'p0_', idCounters = { obj: 0, };
+      var idFactory = new IdFactoryMock({
+        prefix: 'p0_',
+        startObjId: 0,
+      });
 
       var annotation1 = annotationFactory.create(xref, annotationDict,
-                                                 pdfManagerMock,
-                                                 uniquePrefix, idCounters);
+                                                 pdfManagerMock, idFactory);
       var annotation2 = annotationFactory.create(xref, annotationDict,
-                                                 pdfManagerMock,
-                                                 uniquePrefix, idCounters);
+                                                 pdfManagerMock, idFactory);
       var data1 = annotation1.data, data2 = annotation2.data;
       expect(data1.annotationType).toEqual(AnnotationType.LINK);
       expect(data2.annotationType).toEqual(AnnotationType.LINK);
@@ -147,7 +161,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toBeUndefined();
     });
@@ -332,7 +346,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -360,7 +374,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -393,7 +407,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -423,7 +437,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -452,7 +466,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -484,7 +498,7 @@ describe('Annotation layer', function() {
       });
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManager);
+                                                pdfManager, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -513,7 +527,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -543,7 +557,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -583,7 +597,7 @@ describe('Annotation layer', function() {
       });
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManager);
+                                                pdfManager, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -617,7 +631,8 @@ describe('Annotation layer', function() {
         ]);
 
         var annotation = annotationFactory.create(xref, annotationRef,
-                                                  pdfManagerMock);
+                                                  pdfManagerMock,
+                                                  idFactoryMock);
         var data = annotation.data;
         expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -665,7 +680,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -686,7 +701,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -709,7 +724,7 @@ describe('Annotation layer', function() {
       ]);
 
       var annotation = annotationFactory.create(xref, annotationRef,
-                                                pdfManagerMock);
+                                                pdfManagerMock, idFactoryMock);
       var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.LINK);
 
@@ -741,10 +756,11 @@ describe('Annotation layer', function() {
         { ref: widgetRef, data: widgetDict, }
       ]);
 
-      var widgetAnnotation = annotationFactory.create(xref, widgetRef,
-                                                      pdfManagerMock);
-      var data = widgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, widgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.fieldName).toEqual('');
     });
 
@@ -757,10 +773,11 @@ describe('Annotation layer', function() {
         { ref: widgetRef, data: widgetDict, }
       ]);
 
-      var widgetAnnotation = annotationFactory.create(xref, widgetRef,
-                                                      pdfManagerMock);
-      var data = widgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, widgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.fieldName).toEqual('foo');
     });
 
@@ -780,10 +797,11 @@ describe('Annotation layer', function() {
         { ref: widgetRef, data: widgetDict, }
       ]);
 
-      var widgetAnnotation = annotationFactory.create(xref, widgetRef,
-                                                      pdfManagerMock);
-      var data = widgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, widgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.fieldName).toEqual('foo.bar.baz');
     });
   });
@@ -811,13 +829,16 @@ describe('Annotation layer', function() {
         { ref: textWidgetRef, data: textWidgetDict, }
       ]);
 
-      var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                          pdfManagerMock);
-      expect(textWidgetAnnotation.data.textAlignment).toEqual(null);
-      expect(textWidgetAnnotation.data.maxLen).toEqual(null);
-      expect(textWidgetAnnotation.data.readOnly).toEqual(false);
-      expect(textWidgetAnnotation.data.multiLine).toEqual(false);
-      expect(textWidgetAnnotation.data.comb).toEqual(false);
+      var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.textAlignment).toEqual(null);
+      expect(data.maxLen).toEqual(null);
+      expect(data.readOnly).toEqual(false);
+      expect(data.multiLine).toEqual(false);
+      expect(data.comb).toEqual(false);
     });
 
     it('should not set invalid text alignment, maximum length and flags',
@@ -831,13 +852,16 @@ describe('Annotation layer', function() {
         { ref: textWidgetRef, data: textWidgetDict, }
       ]);
 
-      var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                          pdfManagerMock);
-      expect(textWidgetAnnotation.data.textAlignment).toEqual(null);
-      expect(textWidgetAnnotation.data.maxLen).toEqual(null);
-      expect(textWidgetAnnotation.data.readOnly).toEqual(false);
-      expect(textWidgetAnnotation.data.multiLine).toEqual(false);
-      expect(textWidgetAnnotation.data.comb).toEqual(false);
+      var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.textAlignment).toEqual(null);
+      expect(data.maxLen).toEqual(null);
+      expect(data.readOnly).toEqual(false);
+      expect(data.multiLine).toEqual(false);
+      expect(data.comb).toEqual(false);
     });
 
     it('should set valid text alignment, maximum length and flags',
@@ -852,12 +876,15 @@ describe('Annotation layer', function() {
         { ref: textWidgetRef, data: textWidgetDict, }
       ]);
 
-      var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                          pdfManagerMock);
-      expect(textWidgetAnnotation.data.textAlignment).toEqual(1);
-      expect(textWidgetAnnotation.data.maxLen).toEqual(20);
-      expect(textWidgetAnnotation.data.readOnly).toEqual(true);
-      expect(textWidgetAnnotation.data.multiLine).toEqual(true);
+      var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.textAlignment).toEqual(1);
+      expect(data.maxLen).toEqual(20);
+      expect(data.readOnly).toEqual(true);
+      expect(data.multiLine).toEqual(true);
     });
 
     it('should reject comb fields without a maximum length', function() {
@@ -868,9 +895,12 @@ describe('Annotation layer', function() {
         { ref: textWidgetRef, data: textWidgetDict, }
       ]);
 
-      var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                          pdfManagerMock);
-      expect(textWidgetAnnotation.data.comb).toEqual(false);
+      var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.comb).toEqual(false);
     });
 
     it('should accept comb fields with a maximum length', function() {
@@ -882,9 +912,12 @@ describe('Annotation layer', function() {
         { ref: textWidgetRef, data: textWidgetDict, }
       ]);
 
-      var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                          pdfManagerMock);
-      expect(textWidgetAnnotation.data.comb).toEqual(true);
+      var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.comb).toEqual(true);
     });
 
     it('should only accept comb fields when the flags are valid', function() {
@@ -907,10 +940,14 @@ describe('Annotation layer', function() {
           { ref: textWidgetRef, data: textWidgetDict, }
         ]);
 
-        var textWidgetAnnotation = annotationFactory.create(xref, textWidgetRef,
-                                                            pdfManagerMock);
+        var annotation = annotationFactory.create(xref, textWidgetRef,
+                                                  pdfManagerMock,
+                                                  idFactoryMock);
+        var data = annotation.data;
+        expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
         var valid = (invalidFieldFlags.length === 0);
-        expect(textWidgetAnnotation.data.comb).toEqual(valid);
+        expect(data.comb).toEqual(valid);
 
         // Remove the last invalid flag for the next iteration.
         if (!valid) {
@@ -944,11 +981,14 @@ describe('Annotation layer', function() {
         { ref: buttonWidgetRef, data: buttonWidgetDict, }
       ]);
 
-      var buttonWidgetAnnotation =
-        annotationFactory.create(xref, buttonWidgetRef);
-      expect(buttonWidgetAnnotation.data.checkBox).toEqual(true);
-      expect(buttonWidgetAnnotation.data.fieldValue).toEqual('1');
-      expect(buttonWidgetAnnotation.data.radioButton).toEqual(false);
+      var annotation = annotationFactory.create(xref, buttonWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.checkBox).toEqual(true);
+      expect(data.fieldValue).toEqual('1');
+      expect(data.radioButton).toEqual(false);
     });
 
     it('should handle radio buttons', function() {
@@ -970,12 +1010,15 @@ describe('Annotation layer', function() {
         { ref: buttonWidgetRef, data: buttonWidgetDict, }
       ]);
 
-      var buttonWidgetAnnotation =
-        annotationFactory.create(xref, buttonWidgetRef);
-      expect(buttonWidgetAnnotation.data.checkBox).toEqual(false);
-      expect(buttonWidgetAnnotation.data.radioButton).toEqual(true);
-      expect(buttonWidgetAnnotation.data.fieldValue).toEqual('1');
-      expect(buttonWidgetAnnotation.data.buttonValue).toEqual('2');
+      var annotation = annotationFactory.create(xref, buttonWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
+      expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
+      expect(data.checkBox).toEqual(false);
+      expect(data.radioButton).toEqual(true);
+      expect(data.fieldValue).toEqual('1');
+      expect(data.buttonValue).toEqual('2');
     });
   });
 
@@ -1001,11 +1044,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.options).toEqual([]);
     });
 
@@ -1036,11 +1079,11 @@ describe('Annotation layer', function() {
         { ref: optionOneRef, data: optionOneArr, },
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.options).toEqual(expected);
     });
 
@@ -1068,11 +1111,11 @@ describe('Annotation layer', function() {
         { ref: optionBarRef, data: optionBarStr, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.options).toEqual(expected);
     });
 
@@ -1086,11 +1129,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.fieldValue).toEqual(fieldValue);
     });
 
@@ -1104,11 +1147,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.fieldValue).toEqual([fieldValue]);
     });
 
@@ -1118,11 +1161,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.readOnly).toEqual(false);
       expect(data.combo).toEqual(false);
       expect(data.multiSelect).toEqual(false);
@@ -1136,11 +1179,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.readOnly).toEqual(false);
       expect(data.combo).toEqual(false);
       expect(data.multiSelect).toEqual(false);
@@ -1156,11 +1199,11 @@ describe('Annotation layer', function() {
         { ref: choiceWidgetRef, data: choiceWidgetDict, }
       ]);
 
-      var choiceWidgetAnnotation = annotationFactory.create(xref,
-                                                            choiceWidgetRef,
-                                                            pdfManagerMock);
-      var data = choiceWidgetAnnotation.data;
+      var annotation = annotationFactory.create(xref, choiceWidgetRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.WIDGET);
+
       expect(data.readOnly).toEqual(true);
       expect(data.combo).toEqual(true);
       expect(data.multiSelect).toEqual(true);
@@ -1217,15 +1260,15 @@ describe('Annotation layer', function() {
         { ref: popupRef, data: popupDict, }
       ]);
 
-      var popupAnnotation = annotationFactory.create(xref, popupRef,
-                                                     pdfManagerMock);
-      var data = popupAnnotation.data;
+      var annotation = annotationFactory.create(xref, popupRef,
+                                                pdfManagerMock, idFactoryMock);
+      var data = annotation.data;
       expect(data.annotationType).toEqual(AnnotationType.POPUP);
 
       // Should not modify the `annotationFlags` returned e.g. through the API.
       expect(data.annotationFlags).toEqual(25);
       // The Popup should inherit the `viewable` property of the parent.
-      expect(popupAnnotation.viewable).toEqual(true);
+      expect(annotation.viewable).toEqual(true);
     });
   });
 });
diff --git a/test/unit/clitests.json b/test/unit/clitests.json
index fbf81d93c..e1635a9b4 100644
--- a/test/unit/clitests.json
+++ b/test/unit/clitests.json
@@ -3,6 +3,7 @@
   "spec_files": [
     "cff_parser_spec.js",
     "crypto_spec.js",
+    "document_spec.js",
     "dom_utils_spec.js",
     "evaluator_spec.js",
     "fonts_spec.js",
diff --git a/test/unit/document_spec.js b/test/unit/document_spec.js
new file mode 100644
index 000000000..cdec2ae6b
--- /dev/null
+++ b/test/unit/document_spec.js
@@ -0,0 +1,56 @@
+/* Copyright 2017 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+(function (root, factory) {
+  if (typeof define === 'function' && define.amd) {
+    define('pdfjs-test/unit/document_spec', ['exports', 'pdfjs/core/document'],
+      factory);
+  } else if (typeof exports !== 'undefined') {
+    factory(exports, require('../../src/core/document.js'));
+  } else {
+    factory((root.pdfjsTestUnitDocumentSpec = {}),
+      root.pdfjsCoreDocument);
+  }
+}(this, function (exports, coreDocument) {
+
+var Page = coreDocument.Page;
+
+describe('document', function () {
+  describe('Page', function () {
+    it('should create correct objId using the idFactory', function () {
+      var page1 = new Page(/* pdfManager = */ { }, /* xref = */ null,
+                           /* pageIndex = */ 0,
+                           /* pageDict = */ null, /* ref = */ null,
+                           /* fontCache = */ null);
+      var page2 = new Page(/* pdfManager = */ { }, /* xref = */ null,
+                           /* pageIndex = */ 1,
+                           /* pageDict = */ null, /* ref = */ null,
+                           /* fontCache = */ null);
+
+      var idFactory1 = page1.idFactory, idFactory2 = page2.idFactory;
+
+      expect(idFactory1.createObjId()).toEqual('p0_1');
+      expect(idFactory1.createObjId()).toEqual('p0_2');
+
+      expect(idFactory2.createObjId()).toEqual('p1_1');
+      expect(idFactory2.createObjId()).toEqual('p1_2');
+
+      expect(idFactory1.createObjId()).toEqual('p0_3');
+      expect(idFactory1.createObjId()).toEqual('p0_4');
+    });
+  });
+});
+}));
diff --git a/test/unit/jasmine-boot.js b/test/unit/jasmine-boot.js
index f30578a90..b010e4f7e 100644
--- a/test/unit/jasmine-boot.js
+++ b/test/unit/jasmine-boot.js
@@ -48,23 +48,22 @@ function initializePDFJS(callback) {
   require(['pdfjs/display/global', 'pdfjs-test/unit/annotation_layer_spec',
            'pdfjs-test/unit/api_spec', 'pdfjs-test/unit/cff_parser_spec',
            'pdfjs-test/unit/cmap_spec', 'pdfjs-test/unit/crypto_spec',
-           'pdfjs-test/unit/dom_utils_spec', 'pdfjs-test/unit/evaluator_spec',
-           'pdfjs-test/unit/fonts_spec', 'pdfjs-test/unit/function_spec',
-           'pdfjs-test/unit/metadata_spec', 'pdfjs-test/unit/murmurhash3_spec',
-           'pdfjs-test/unit/network_spec', 'pdfjs-test/unit/parser_spec',
-           'pdfjs-test/unit/primitives_spec', 'pdfjs-test/unit/stream_spec',
-           'pdfjs-test/unit/type1_parser_spec', 'pdfjs-test/unit/ui_utils_spec',
-           'pdfjs-test/unit/unicode_spec', 'pdfjs-test/unit/util_spec'],
-    function (displayGlobal, testUnitAnnotationLayerSpec,
-              testUnitApiSpec, testUnitCFFParserSpec,
-              testUnitCMapSpec, testUnitCryptoSpec,
-              testUnitDOMUtilsSpec, testUnitEvaluatorSpec,
-              testUnitFontsSpec, testUnitFunctionSpec,
-              testUnitMetadataSpec, testUnitMurmurHash3Spec,
-              testUnitNetworkSpec, testUnitParserSpec,
+           'pdfjs-test/unit/document_spec', 'pdfjs-test/unit/dom_utils_spec',
+           'pdfjs-test/unit/evaluator_spec', 'pdfjs-test/unit/fonts_spec',
+           'pdfjs-test/unit/function_spec', 'pdfjs-test/unit/metadata_spec',
+           'pdfjs-test/unit/murmurhash3_spec', 'pdfjs-test/unit/network_spec',
+           'pdfjs-test/unit/parser_spec', 'pdfjs-test/unit/primitives_spec',
+           'pdfjs-test/unit/stream_spec', 'pdfjs-test/unit/type1_parser_spec',
+           'pdfjs-test/unit/ui_utils_spec', 'pdfjs-test/unit/unicode_spec',
+           'pdfjs-test/unit/util_spec'],
+    function (displayGlobal, testUnitAnnotationLayerSpec, testUnitApiSpec,
+              testUnitCFFParserSpec, testUnitCMapSpec, testUnitCryptoSpec,
+              testUnitDocumentSpec, testUnitDOMUtilsSpec, testUnitEvaluatorSpec,
+              testUnitFontsSpec, testUnitFunctionSpec, testUnitMetadataSpec,
+              testUnitMurmurHash3Spec, testUnitNetworkSpec, testUnitParserSpec,
               testUnitPrimitivesSpec, testUnitStreamSpec,
-              testUnitType1ParserSpec, testUnitUiUtilsSpec,
-              testUnitUnicodeSpec, testUnitUtilSpec) {
+              testUnitType1ParserSpec, testUnitUiUtilsSpec, testUnitUnicodeSpec,
+              testUnitUtilSpec) {
 
       // Configure the worker.
       displayGlobal.PDFJS.workerSrc = '../../src/worker_loader.js';