diff --git a/.eslintrc.json b/.eslintrc.json
index 634e0a66c6..c25f61e55a 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -6,6 +6,7 @@
   "rules": {
     "no-console": "off",
     "no-var": "error",
+    "semi": "error",
     "strict": "error",
     "valid-jsdoc": ["error", {
       "requireReturn": false,
diff --git a/lib/elements/array-selector.html b/lib/elements/array-selector.html
index bb1381674c..9deba97345 100644
--- a/lib/elements/array-selector.html
+++ b/lib/elements/array-selector.html
@@ -105,11 +105,11 @@
             value: false
           }
 
-        }
+        };
       }
 
       static get observers() {
-        return ['__updateSelection(multi, items.*)']
+        return ['__updateSelection(multi, items.*)'];
       }
 
       constructor() {
@@ -222,7 +222,7 @@
         // order: selected array index
         this.__selectedMap = new Map();
         // Initialize selection
-        this.selected = this.multi ? [] : null
+        this.selected = this.multi ? [] : null;
         this.selectedItem = null;
       }
 
@@ -416,7 +416,7 @@
   class ArraySelector extends baseArraySelector {
     // Not needed to find template; can be removed once the analyzer
     // can find the tag name from customElements.define call
-    static get is() { return 'array-selector' }
+    static get is() { return 'array-selector'; }
   }
   customElements.define(ArraySelector.is, ArraySelector);
   Polymer.ArraySelector = ArraySelector;
diff --git a/lib/elements/dom-bind.html b/lib/elements/dom-bind.html
index ec6c547009..3a32c7f926 100644
--- a/lib/elements/dom-bind.html
+++ b/lib/elements/dom-bind.html
@@ -52,7 +52,7 @@
      */
     class DomBind extends domBindBase {
 
-      static get observedAttributes() { return ['mutable-data'] }
+      static get observedAttributes() { return ['mutable-data']; }
 
       constructor() {
         super();
@@ -104,7 +104,7 @@
               } else {
                 throw new Error('dom-bind requires a <template> child');
               }
-            })
+            });
             observer.observe(this, {childList: true});
             return;
           }
diff --git a/lib/elements/dom-if.html b/lib/elements/dom-if.html
index 902b5626ae..a1903b0dc5 100644
--- a/lib/elements/dom-if.html
+++ b/lib/elements/dom-if.html
@@ -80,7 +80,7 @@
           observer: '__debounceRender'
         }
 
-      }
+      };
 
     }
 
@@ -181,7 +181,7 @@
               } else {
                 throw new Error('dom-if requires a <template> child');
               }
-            })
+            });
             observer.observe(this, {childList: true});
             return false;
           }
diff --git a/lib/elements/dom-module.html b/lib/elements/dom-module.html
index 8f785ae865..552d96e089 100644
--- a/lib/elements/dom-module.html
+++ b/lib/elements/dom-module.html
@@ -53,7 +53,7 @@
    */
   class DomModule extends HTMLElement {
 
-    static get observedAttributes() { return ['id'] }
+    static get observedAttributes() { return ['id']; }
 
     /**
      * Retrieves the element specified by the css `selector` in the module
diff --git a/lib/elements/dom-repeat.html b/lib/elements/dom-repeat.html
index 17a1401588..e6c6882149 100644
--- a/lib/elements/dom-repeat.html
+++ b/lib/elements/dom-repeat.html
@@ -267,12 +267,12 @@
           computed: '__computeFrameTime(targetFramerate)'
         }
 
-      }
+      };
 
     }
 
     static get observers() {
-      return [ '__itemsChanged(items.*)' ]
+      return [ '__itemsChanged(items.*)' ];
     }
 
     constructor() {
@@ -327,7 +327,7 @@
             } else {
               throw new Error('dom-repeat requires a <template> child');
             }
-          })
+          });
           observer.observe(this, {childList: true});
           return false;
         }
diff --git a/lib/legacy/class.html b/lib/legacy/class.html
index 4c2b91f985..f52f042c09 100644
--- a/lib/legacy/class.html
+++ b/lib/legacy/class.html
@@ -24,7 +24,7 @@
       attributeChanged: true,
       // meta objects
       behaviors: true
-    }
+    };
 
     /**
      * Applies a "legacy" behavior or array of behaviors to the provided class.
@@ -240,7 +240,7 @@
        }
       }
 
-      PolymerGenerated.generatedFrom = info
+      PolymerGenerated.generatedFrom = info;
 
       for (let p in info) {
         // NOTE: cannot copy `metaProps` methods onto prototype at least because
@@ -335,7 +335,7 @@
       // decorate klass with registration info
       klass.is = info.is;
       return klass;
-    }
+    };
 
     Polymer.mixinBehaviors = mixinBehaviors;
 
diff --git a/lib/legacy/legacy-element-mixin.html b/lib/legacy/legacy-element-mixin.html
index 4707b9e9ff..84df920ed0 100644
--- a/lib/legacy/legacy-element-mixin.html
+++ b/lib/legacy/legacy-element-mixin.html
@@ -369,7 +369,7 @@
         });
         event.detail = detail;
         let node = options.node || this;
-        node.dispatchEvent(event)
+        node.dispatchEvent(event);
         return event;
       }
 
@@ -687,7 +687,7 @@
        * @param {string} jobName The name of the debouncer started with `debounce`
        */
       cancelDebouncer(jobName) {
-        this._debouncers = this._debouncers || {}
+        this._debouncers = this._debouncers || {};
         let debouncer = this._debouncers[jobName];
         if (debouncer) {
           debouncer.cancel();
@@ -927,7 +927,7 @@
        * @param {...*} args Array of strings or objects to log
        */
       _error(...args) {
-        this._logger('error', args)
+        this._logger('error', args);
       }
 
       /**
diff --git a/lib/legacy/polymer.dom.html b/lib/legacy/polymer.dom.html
index a8c4df1ff6..c15820c430 100644
--- a/lib/legacy/polymer.dom.html
+++ b/lib/legacy/polymer.dom.html
@@ -34,7 +34,7 @@
    */
   const matchesSelector = function(node, selector) {
     return normalizedMatchesSelector.call(node, selector);
-  }
+  };
 
   /**
    * Node API wrapper class returned from `Polymer.dom.(target)` when
@@ -196,7 +196,7 @@
       let method = methods[i];
       proto[method] = /** @this {DomApi} */ function() {
         return this.node[method].apply(this.node, arguments);
-      }
+      };
     }
   }
 
diff --git a/lib/mixins/element-mixin.html b/lib/mixins/element-mixin.html
index 200d06f31b..629751fcde 100644
--- a/lib/mixins/element-mixin.html
+++ b/lib/mixins/element-mixin.html
@@ -808,7 +808,7 @@
      * @private
      */
     _regLog: function(prototype) {
-      console.log('[' + prototype.is + ']: registered')
+      console.log('[' + prototype.is + ']: registered');
     },
     /**
      * Registers a class prototype for telemetry purposes.
diff --git a/lib/mixins/property-accessors.html b/lib/mixins/property-accessors.html
index 3c1364cc57..c1977997cd 100644
--- a/lib/mixins/property-accessors.html
+++ b/lib/mixins/property-accessors.html
@@ -468,7 +468,7 @@
        */
       _setPendingProperty(property, value) {
         let old = this.__data[property];
-        let changed = this._shouldPropertyChange(property, value, old)
+        let changed = this._shouldPropertyChange(property, value, old);
         if (changed) {
           if (!this.__dataPending) {
             this.__dataPending = {};
@@ -528,7 +528,7 @@
             this._initializeInstanceProperties(this.__dataInstanceProps);
             this.__dataInstanceProps = null;
           }
-          this.ready()
+          this.ready();
         }
       }
 
diff --git a/lib/mixins/property-effects.html b/lib/mixins/property-effects.html
index 69464b1c9f..be7118c239 100644
--- a/lib/mixins/property-effects.html
+++ b/lib/mixins/property-effects.html
@@ -42,7 +42,7 @@
     PROPAGATE: '__propagateEffects',
     OBSERVE: '__observeEffects',
     READ_ONLY: '__readOnly'
-  }
+  };
 
   /**
    * @typedef {{
@@ -1979,7 +1979,7 @@
         if (protectedSetter) {
           this['_set' + upper(property)] = /** @this {PropertyEffects} */function(value) {
             this._setProperty(property, value);
-          }
+          };
         }
       }
 
@@ -2687,7 +2687,7 @@
       }
     }
 
-  }
+  };
 
 })();
 </script>
diff --git a/lib/utils/array-splice.html b/lib/utils/array-splice.html
index b9ac24cd71..328284dc1e 100644
--- a/lib/utils/array-splice.html
+++ b/lib/utils/array-splice.html
@@ -309,7 +309,7 @@
      * of items added at this location.
      */
     calculateSplices
-  }
+  };
 
 })();
 </script>
\ No newline at end of file
diff --git a/lib/utils/async.html b/lib/utils/async.html
index 5308d500fe..ff07972100 100644
--- a/lib/utils/async.html
+++ b/lib/utils/async.html
@@ -33,7 +33,7 @@
         try {
           cb();
         } catch (e) {
-          setTimeout(() => { throw e });
+          setTimeout(() => { throw e; });
         }
       }
     }
@@ -72,9 +72,9 @@
        */
       after(delay) {
         return  {
-          run(fn) { return setTimeout(fn, delay) },
+          run(fn) { return setTimeout(fn, delay); },
           cancel: window.clearTimeout.bind(window)
-        }
+        };
       },
       /**
        * Enqueues a function called in the next task.
diff --git a/lib/utils/boot.html b/lib/utils/boot.html
index 458e628a71..512cd9e27c 100644
--- a/lib/utils/boot.html
+++ b/lib/utils/boot.html
@@ -27,7 +27,7 @@
    */
   window.Polymer = function(info) {
     return window.Polymer._polymerFn(info);
-  }
+  };
 
   // support user settings on the Polymer object
   if (userPolymer) {
@@ -46,7 +46,7 @@
    */
   window.Polymer._polymerFn = function(info) { // eslint-disable-line no-unused-vars
     throw new Error('Load polymer.html to use the Polymer() function.');
-  }
+  };
   /* eslint-enable */
 
   window.Polymer.version = '2.0.1';
@@ -58,7 +58,7 @@
   */
   window.JSCompiler_renameProperty = function(prop, obj) {
     return prop;
-  }
+  };
   /* eslint-enable */
 
 })();
diff --git a/lib/utils/debounce.html b/lib/utils/debounce.html
index 46096bbe49..7fff476678 100644
--- a/lib/utils/debounce.html
+++ b/lib/utils/debounce.html
@@ -41,7 +41,7 @@
       this._callback = callback;
       this._timer = this._asyncModule.run(() => {
         this._timer = null;
-        this._callback()
+        this._callback();
       });
     }
     /**
diff --git a/lib/utils/flattened-nodes-observer.html b/lib/utils/flattened-nodes-observer.html
index 329c071c0c..78742e3578 100644
--- a/lib/utils/flattened-nodes-observer.html
+++ b/lib/utils/flattened-nodes-observer.html
@@ -95,7 +95,7 @@
       /** @type {function()} */
       this._boundSchedule = () => {
         this._schedule();
-      }
+      };
       this.connect();
       this._schedule();
     }
diff --git a/lib/utils/flush.html b/lib/utils/flush.html
index 0e3384bc4a..331442292d 100644
--- a/lib/utils/flush.html
+++ b/lib/utils/flush.html
@@ -22,7 +22,7 @@
    */
   Polymer.enqueueDebouncer = function(debouncer) {
     debouncerQueue.push(debouncer);
-  }
+  };
 
   function flushDebouncers() {
     const didFlush = Boolean(debouncerQueue.length);
@@ -54,7 +54,7 @@
       }
       debouncers = flushDebouncers();
     } while (shadyDOM || debouncers);
-  }
+  };
 
 })();
 </script>
diff --git a/lib/utils/gestures.html b/lib/utils/gestures.html
index e9fb89feda..451433a639 100644
--- a/lib/utils/gestures.html
+++ b/lib/utils/gestures.html
@@ -45,7 +45,7 @@
   let SUPPORTS_PASSIVE = false;
   (function() {
     try {
-      let opts = Object.defineProperty({}, 'passive', {get: function() {SUPPORTS_PASSIVE = true;}})
+      let opts = Object.defineProperty({}, 'passive', {get: function() {SUPPORTS_PASSIVE = true;}});
       window.addEventListener('test', null, opts);
       window.removeEventListener('test', null, opts);
     } catch(e) {}
diff --git a/lib/utils/import-href.html b/lib/utils/import-href.html
index 65e35dfe33..d1d96d442f 100644
--- a/lib/utils/import-href.html
+++ b/lib/utils/import-href.html
@@ -64,7 +64,7 @@
     let cleanup = function() {
       link.removeEventListener('load', loadListener);
       link.removeEventListener('error', errorListener);
-    }
+    };
     let loadListener = function(event) {
       cleanup();
       // In case of a successful load, cache the load event on the link so
diff --git a/lib/utils/render-status.html b/lib/utils/render-status.html
index ca7175adce..6f44578908 100644
--- a/lib/utils/render-status.html
+++ b/lib/utils/render-status.html
@@ -52,7 +52,7 @@
     } catch(e) {
       setTimeout(() => {
         throw e;
-      })
+      });
     }
   }
 
diff --git a/lib/utils/settings.html b/lib/utils/settings.html
index 5826dedfbc..4846ef5334 100644
--- a/lib/utils/settings.html
+++ b/lib/utils/settings.html
@@ -60,7 +60,7 @@
    */
   Polymer.setRootPath = function(path) {
     Polymer.rootPath = path;
-  }
+  };
 
   /**
    * A global callback used to sanitize any value before inserting it into the DOM. The callback signature is:
@@ -92,6 +92,6 @@
    */
   Polymer.setSanitizeDOMValue = function(newSanitizeDOMValue) {
     Polymer.sanitizeDOMValue = newSanitizeDOMValue;
-  }
+  };
 })();
 </script>
diff --git a/lib/utils/templatize.html b/lib/utils/templatize.html
index 4f6a38d39f..b146c67510 100644
--- a/lib/utils/templatize.html
+++ b/lib/utils/templatize.html
@@ -203,12 +203,12 @@
         let model = this.__parentModel;
         if (!model) {
           let options;
-          model = this
+          model = this;
           do {
             // A template instance's `__dataHost` is a <template>
             // `model.__dataHost.__dataHost` is the template's host
             model = model.__dataHost.__dataHost;
-          } while ((options = model.__templatizeOptions) && !options.parentModel)
+          } while ((options = model.__templatizeOptions) && !options.parentModel);
           this.__parentModel = model;
         }
         return model;
@@ -255,7 +255,7 @@
        * @constructor
        * @extends {base}
        */
-      let klass = class extends base { }
+      let klass = class extends base { };
       klass.prototype.__templatizeOptions = options;
       klass.prototype._bindTemplate(template);
       addNotifyEffects(klass, template, templateInfo, options);
@@ -273,7 +273,7 @@
         if (!klass) {
           let base = options.mutableData ? MutableDataTemplate : DataTemplate;
           klass = templateInfo.templatizeTemplateClass =
-            class TemplatizedTemplate extends base {}
+            class TemplatizedTemplate extends base {};
           // Add template - >instances effects
           // and host <- template effects
           let hostProps = templateInfo.hostProps;
@@ -305,7 +305,7 @@
       return function forwardHostProp(template, prop, props) {
         userForwardHostProp.call(template.__templatizeOwner,
           prop.substring('_host_'.length), props[prop]);
-      }
+      };
     }
 
     function addNotifyEffects(klass, template, templateInfo, options) {
@@ -323,7 +323,7 @@
         for (let hprop in hostProps) {
           klass.prototype._addPropertyEffect(hprop,
             klass.prototype.PROPERTY_EFFECT_TYPES.NOTIFY,
-            {fn: createNotifyHostPropEffect()})
+            {fn: createNotifyHostPropEffect()});
         }
       }
     }
@@ -332,13 +332,13 @@
       return function notifyInstanceProp(inst, prop, props) {
         userNotifyInstanceProp.call(inst.__templatizeOwner,
           inst, prop, props[prop]);
-      }
+      };
     }
 
     function createNotifyHostPropEffect() {
       return function notifyHostProp(inst, prop, props) {
         inst.__dataHost._setPendingPropertyOrPath('_host_' + prop, props[prop], true, true);
-      }
+      };
     }
 
     /**
@@ -512,7 +512,7 @@
         }
         return null;
       }
-    }
+    };
 
     Polymer.Templatize = Templatize;
     Polymer.TemplateInstanceBase = TemplateInstanceBase;