diff --git a/externs/oli.js b/externs/oli.js
index 7f1d49940b..4be5f74d8d 100644
--- a/externs/oli.js
+++ b/externs/oli.js
@@ -10,8 +10,10 @@ var oli;
 
 
 
-/** @interface */
-oli.CollectionEvent;
+/**
+ * @interface
+ */
+oli.CollectionEvent = function() {};
 
 
 /**
@@ -21,8 +23,10 @@ oli.CollectionEvent.prototype.element;
 
 
 
-/** @interface */
-oli.DragBoxEvent;
+/**
+ * @interface
+ */
+oli.DragBoxEvent = function() {};
 
 
 /**
@@ -32,8 +36,10 @@ oli.DragBoxEvent.prototype.coordinate;
 
 
 
-/** @interface */
-oli.DrawEvent;
+/**
+ * @interface
+ */
+oli.DrawEvent = function() {};
 
 
 /**
@@ -43,8 +49,10 @@ oli.DrawEvent.prototype.feature;
 
 
 
-/** @interface */
-oli.ObjectEvent;
+/**
+ * @interface
+ */
+oli.ObjectEvent = function() {};
 
 
 /** @type {string} */
@@ -52,8 +60,10 @@ oli.ObjectEvent.prototype.key;
 
 
 
-/** @interface */
-oli.MapBrowserEvent;
+/**
+ * @interface
+ */
+oli.MapBrowserEvent = function() {};
 
 
 /**
@@ -75,8 +85,10 @@ oli.MapBrowserEvent.prototype.pixel;
 
 
 
-/** @interface */
-oli.MapEvent;
+/**
+ * @interface
+ */
+oli.MapEvent = function() {};
 
 
 /**
@@ -91,11 +103,16 @@ oli.MapEvent.prototype.map;
 oli.MapEvent.prototype.frameState;
 
 
+/**
+ * @type {Object}
+ */
+oli.control;
+
 
 /**
  * @interface
  */
-oli.control.Control;
+oli.control.Control = function() {};
 
 
 /**
@@ -105,9 +122,17 @@ oli.control.Control;
 oli.control.Control.prototype.setMap = function(map) {};
 
 
+/**
+ * @type {Object}
+ */
+oli.interaction;
 
-/** @interface */
-oli.interaction.DragAndDropEvent;
+
+
+/**
+ * @interface
+ */
+oli.interaction.DragAndDropEvent = function() {};
 
 
 /**
@@ -128,9 +153,17 @@ oli.interaction.DragAndDropEvent.prototype.projection;
 oli.interaction.DragAndDropEvent.prototype.file;
 
 
+/**
+ * @type {Object}
+ */
+oli.render;
 
-/** @interface */
-oli.render.Event;
+
+
+/**
+ * @interface
+ */
+oli.render.Event = function() {};
 
 
 /**
@@ -157,9 +190,17 @@ oli.render.Event.prototype.glContext;
 oli.render.Event.prototype.vectorContext;
 
 
+/**
+ * @type {Object}
+ */
+oli.source;
 
-/** @interface */
-oli.source.VectorEvent;
+
+
+/**
+ * @interface
+ */
+oli.source.VectorEvent = function() {};
 
 
 /**
diff --git a/externs/olx.js b/externs/olx.js
index a46aa56d57..ed11d4dc82 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -594,6 +594,13 @@ olx.ViewOptions.prototype.zoom;
 olx.ViewOptions.prototype.zoomFactor;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.animation;
+
+
 /**
  * @typedef {{resolution: number,
  *     start: (number|undefined),
@@ -779,6 +786,13 @@ olx.animation.ZoomOptions.prototype.duration;
 olx.animation.ZoomOptions.prototype.easing;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.control;
+
+
 /**
  * @typedef {{className: (string|undefined),
  *     target: (Element|undefined)}}
@@ -1279,6 +1293,13 @@ olx.control.ZoomToExtentOptions.prototype.tipLabel;
 olx.control.ZoomToExtentOptions.prototype.extent;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.format;
+
+
 /**
  * @typedef {{dataProjection: (ol.proj.ProjectionLike|undefined),
  *     featureProjection: (ol.proj.ProjectionLike|undefined)}}
@@ -1742,6 +1763,13 @@ olx.format.WKTOptions;
 olx.format.WKTOptions.prototype.splitCollection;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.interaction;
+
+
 /**
  * Interactions for the map. Default is `true` for all options.
  * @typedef {{altShiftDragRotate: (boolean|undefined),
@@ -2307,6 +2335,13 @@ olx.interaction.SelectOptions.prototype.removeCondition;
 olx.interaction.SelectOptions.prototype.toggleCondition;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.layer;
+
+
 /**
  * @typedef {{brightness: (number|undefined),
  *     contrast: (number|undefined),
@@ -3097,6 +3132,13 @@ olx.FeatureOverlayOptions.prototype.map;
 olx.FeatureOverlayOptions.prototype.style;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.source;
+
+
 /**
  * @typedef {{culture: (string|undefined),
  *     key: string,
@@ -5241,6 +5283,13 @@ olx.source.ZoomifyOptions.prototype.tierSizeCalculation;
 olx.source.ZoomifyOptions.prototype.size;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.style;
+
+
 /**
  * @typedef {{fill: (ol.style.Fill|undefined),
  *     radius: number,
@@ -5662,6 +5711,13 @@ olx.style.StyleOptions.prototype.text;
 olx.style.StyleOptions.prototype.zIndex;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.tilegrid;
+
+
 /**
  * @typedef {{minZoom: (number|undefined),
  *     origin: (ol.Coordinate|undefined),
@@ -5847,6 +5903,13 @@ olx.tilegrid.ZoomifyOptions;
 olx.tilegrid.ZoomifyOptions.prototype.resolutions;
 
 
+/**
+ * Namespace.
+ * @type {Object}
+ */
+olx.View;
+
+
 /**
  * @typedef {{padding: !Array.<number>,
  *     constrainResolution: (boolean|undefined),
diff --git a/externs/readme.md b/externs/readme.md
index cbecf2b70c..992c354fe3 100644
--- a/externs/readme.md
+++ b/externs/readme.md
@@ -11,8 +11,10 @@ These two files are special externs that belong to ol3, and this document explai
 For events, we make properties available to the application. Methods can be made available by just marking them with the `@api` annotation directly where they are defined; properties should also be added to `oli.js`:
 
 ```js
-/** @interface */
-oli.MapBrowserEvent;
+/**
+ * @interface
+ */
+oli.MapBrowserEvent = function() {};
 
 /**
  * @type {ol.Coordinate}
@@ -48,7 +50,7 @@ For custom subclasses in applications, which can be created using `ol.inherits`,
 /**
  * @interface
  */
-oli.control.Control;
+oli.control.Control = function() {};
 
 /**
  * @param {ol.Map} map Map.