diff --git a/lib/mixins/element-mixin.html b/lib/mixins/element-mixin.html
index 629751fcde..20f3e79c6e 100644
--- a/lib/mixins/element-mixin.html
+++ b/lib/mixins/element-mixin.html
@@ -116,7 +116,7 @@
         JSCompiler_renameProperty('__ownProperties', klass))) {
         klass.__ownProperties =
           klass.hasOwnProperty(JSCompiler_renameProperty('properties', klass)) ?
-          /** @type PolymerElementConstructor */ (klass).properties : {};
+          /** @type {PolymerElementConstructor} */ (klass).properties : {};
       }
       return klass.__ownProperties;
     }
@@ -134,7 +134,7 @@
         JSCompiler_renameProperty('__ownObservers', klass))) {
         klass.__ownObservers =
           klass.hasOwnProperty(JSCompiler_renameProperty('observers', klass)) ?
-          /** @type PolymerElementConstructor */ (klass).observers : [];
+          /** @type {PolymerElementConstructor} */ (klass).observers : [];
       }
       return klass.__ownObservers;
     }
@@ -178,7 +178,7 @@
         let superCtor = Object.getPrototypeOf(klass.prototype).constructor;
         if (superCtor.prototype instanceof PolymerElement) {
           klass.__classProperties = Object.assign(
-            Object.create(propertiesForClass(/** @type PolymerElementConstructor */(superCtor))),
+            Object.create(propertiesForClass(/** @type {PolymerElementConstructor} */(superCtor))),
             klass.__classProperties);
         }
       }
@@ -232,7 +232,7 @@
      * @private
      */
     function finalizeClassAndSuper(klass) {
-      let proto = /** @type PolymerElementConstructor */ (klass).prototype;
+      let proto = /** @type {PolymerElementConstructor} */ (klass).prototype;
       let superCtor = Object.getPrototypeOf(proto).constructor;
       if (superCtor.prototype instanceof PolymerElement) {
         superCtor.finalize();
@@ -251,7 +251,7 @@
      */
     function finalizeClass(klass) {
       klass.__finalized = true;
-      let proto = /** @type PolymerElementConstructor */ (klass).prototype;
+      let proto = /** @type {PolymerElementConstructor} */ (klass).prototype;
       if (klass.hasOwnProperty(
         JSCompiler_renameProperty('is', klass)) && klass.is) {
         Polymer.telemetry.register(proto);
@@ -265,7 +265,7 @@
         finalizeObservers(proto, observers, props);
       }
       // note: create "working" template that is finalized at instance time
-      let template = /** @type PolymerElementConstructor */ (klass).template;
+      let template = /** @type {PolymerElementConstructor} */ (klass).template;
       if (template) {
         if (typeof template === 'string') {
           let t = document.createElement('template');
@@ -515,11 +515,11 @@
       static get template() {
         if (!this.hasOwnProperty(JSCompiler_renameProperty('_template', this))) {
           this._template = Polymer.DomModule && Polymer.DomModule.import(
-            /** @type PolymerElementConstructor*/ (this).is, 'template') ||
+            /** @type {PolymerElementConstructor}*/ (this).is, 'template') ||
             // note: implemented so a subclass can retrieve the super
             // template; call the super impl this way so that `this` points
             // to the superclass.
-            Object.getPrototypeOf(/** @type PolymerElementConstructor*/ (this).prototype).constructor.template;
+            Object.getPrototypeOf(/** @type {PolymerElementConstructor}*/ (this).prototype).constructor.template;
         }
         return this._template;
       }
@@ -537,9 +537,9 @@
        */
       static get importPath() {
         if (!this.hasOwnProperty(JSCompiler_renameProperty('_importPath', this))) {
-            const module = Polymer.DomModule && Polymer.DomModule.import(/** @type PolymerElementConstructor */ (this).is);
+            const module = Polymer.DomModule && Polymer.DomModule.import(/** @type {PolymerElementConstructor} */ (this).is);
             this._importPath = module ? module.assetpath : '' ||
-            Object.getPrototypeOf(/** @type PolymerElementConstructor*/ (this).prototype).constructor.importPath;
+            Object.getPrototypeOf(/** @type {PolymerElementConstructor}*/ (this).prototype).constructor.importPath;
         }
         return this._importPath;
       }
diff --git a/lib/mixins/property-accessors.html b/lib/mixins/property-accessors.html
index c1977997cd..cbc2d76092 100644
--- a/lib/mixins/property-accessors.html
+++ b/lib/mixins/property-accessors.html
@@ -359,7 +359,7 @@
 
           case Object:
             try {
-              outValue = JSON.parse(/** @type string */(value));
+              outValue = JSON.parse(/** @type {string} */(value));
             } catch(x) {
               // allow non-JSON literals like Strings and Numbers
             }
@@ -367,7 +367,7 @@
 
           case Array:
             try {
-              outValue = JSON.parse(/** @type string */(value));
+              outValue = JSON.parse(/** @type {string} */(value));
             } catch(x) {
               outValue = null;
               console.warn(`Polymer::Attributes: couldn't decode Array as JSON: ${value}`);
diff --git a/lib/mixins/template-stamp.html b/lib/mixins/template-stamp.html
index ffbadc4ac4..f277ff6a6b 100644
--- a/lib/mixins/template-stamp.html
+++ b/lib/mixins/template-stamp.html
@@ -227,7 +227,7 @@
        */
       static _parseTemplateNode(node, templateInfo, nodeInfo) {
         let noted;
-        let element = /** @type Element */(node);
+        let element = /** @type {Element} */(node);
         if (element.localName == 'template' && !element.hasAttribute('preserve-content')) {
           noted = this._parseTemplateNestedTemplate(element, templateInfo, nodeInfo) || noted;
         } else if (element.localName === 'slot') {
@@ -418,7 +418,7 @@
         let templateInfo = this.constructor._parseTemplate(template);
         let nodeInfo = templateInfo.nodeInfoList;
         let content = templateInfo.content || template.content;
-        let dom = /** @type DocumentFragment */ (document.importNode(content, true));
+        let dom = /** @type {DocumentFragment} */ (document.importNode(content, true));
         // NOTE: ShadyDom optimization indicating there is an insertion point
         dom.__noInsertionPoint = !templateInfo.hasInsertionPoint;
         let nodes = dom.nodeList = new Array(nodeInfo.length);