diff --git a/src/tooltip/tooltip.js b/src/tooltip/tooltip.js
index f4976053..924dc65b 100644
--- a/src/tooltip/tooltip.js
+++ b/src/tooltip/tooltip.js
@@ -15,132 +15,136 @@
  * limitations under the License.
  */
 
-/**
- * Class constructor for Tooltip MDL component.
- * Implements MDL component design pattern defined at:
- * https://github.com/jasonmayes/mdl-component-design-pattern
- * @param {HTMLElement} element The element that will be upgraded.
- */
-function MaterialTooltip(element) {
+(function() {
   'use strict';
 
-  this.element_ = element;
+  /**
+   * Class constructor for Tooltip MDL component.
+   * Implements MDL component design pattern defined at:
+   * https://github.com/jasonmayes/mdl-component-design-pattern
+   *
+   * @param {HTMLElement} element The element that will be upgraded.
+   */
+  var MaterialTooltip = function MaterialTooltip(element) {
+    this.element_ = element;
 
-  // Initialize instance.
-  this.init();
-}
+    // Initialize instance.
+    this.init();
+  };
+  window.MaterialTooltip = MaterialTooltip;
 
-/**
- * Store constants in one place so they can be updated easily.
- * @enum {string | number}
- * @private
- */
-MaterialTooltip.prototype.Constant_ = {
-  // None for now.
-};
+  /**
+   * Store constants in one place so they can be updated easily.
+   *
+   * @enum {String | Number}
+   * @private
+   */
+  MaterialTooltip.prototype.Constant_ = {
+    // None for now.
+  };
 
-/**
- * Store strings for class names defined by this component that are used in
- * JavaScript. This allows us to simply change it in one place should we
- * decide to modify at a later date.
- * @enum {string}
- * @private
- */
-MaterialTooltip.prototype.CssClasses_ = {
-  IS_ACTIVE: 'is-active'
-};
+  /**
+   * Store strings for class names defined by this component that are used in
+   * JavaScript. This allows us to simply change it in one place should we
+   * decide to modify at a later date.
+   *
+   * @enum {String}
+   * @private
+   */
+  MaterialTooltip.prototype.CssClasses_ = {
+    IS_ACTIVE: 'is-active'
+  };
 
-/**
- * Handle mouseenter for tooltip.
- * @param {Event} event The event that fired.
- * @private
- */
-MaterialTooltip.prototype.handleMouseEnter_ = function(event) {
-  'use strict';
+  /**
+   * Handle mouseenter for tooltip.
+   *
+   * @param {Event} event The event that fired.
+   * @private
+   */
+  MaterialTooltip.prototype.handleMouseEnter_ = function(event) {
+    event.stopPropagation();
+    var props = event.target.getBoundingClientRect();
+    var left = props.left + (props.width / 2);
+    var marginLeft = -1 * (this.element_.offsetWidth / 2);
 
-  event.stopPropagation();
-  var props = event.target.getBoundingClientRect();
-  var left = props.left + (props.width / 2);
-  var marginLeft = -1 * (this.element_.offsetWidth / 2);
-
-  if (left + marginLeft < 0) {
-    this.element_.style.left = 0;
-    this.element_.style.marginLeft = 0;
-  } else {
-    this.element_.style.left = left + 'px';
-    this.element_.style.marginLeft = marginLeft + 'px';
-  }
-
-  this.element_.style.top = props.top + props.height + 10 + 'px';
-  this.element_.classList.add(this.CssClasses_.IS_ACTIVE);
-  window.addEventListener('scroll', this.boundMouseLeaveHandler, false);
-  window.addEventListener('touchmove', this.boundMouseLeaveHandler, false);
-};
-
-/**
- * Handle mouseleave for tooltip.
- * @param {Event} event The event that fired.
- * @private
- */
-MaterialTooltip.prototype.handleMouseLeave_ = function(event) {
-  'use strict';
-
-  event.stopPropagation();
-  this.element_.classList.remove(this.CssClasses_.IS_ACTIVE);
-  window.removeEventListener('scroll', this.boundMouseLeaveHandler);
-  window.removeEventListener('touchmove', this.boundMouseLeaveHandler, false);
-};
-
-/**
- * Initialize element.
- */
-MaterialTooltip.prototype.init = function() {
-  'use strict';
-
-  if (this.element_) {
-    var forElId = this.element_.getAttribute('for');
-
-    if (forElId) {
-      this.forElement_ = document.getElementById(forElId);
+    if (left + marginLeft < 0) {
+      this.element_.style.left = 0;
+      this.element_.style.marginLeft = 0;
+    } else {
+      this.element_.style.left = left + 'px';
+      this.element_.style.marginLeft = marginLeft + 'px';
     }
 
-    if (this.forElement_) {
-      // Tabindex needs to be set for `blur` events to be emitted
-      if (!this.forElement_.getAttribute('tabindex')) {
-        this.forElement_.setAttribute('tabindex', '0');
+    this.element_.style.top = props.top + props.height + 10 + 'px';
+    this.element_.classList.add(this.CssClasses_.IS_ACTIVE);
+    window.addEventListener('scroll', this.boundMouseLeaveHandler, false);
+    window.addEventListener('touchmove', this.boundMouseLeaveHandler, false);
+  };
+
+  /**
+   * Handle mouseleave for tooltip.
+   *
+   * @param {Event} event The event that fired.
+   * @private
+   */
+  MaterialTooltip.prototype.handleMouseLeave_ = function(event) {
+    event.stopPropagation();
+    this.element_.classList.remove(this.CssClasses_.IS_ACTIVE);
+    window.removeEventListener('scroll', this.boundMouseLeaveHandler);
+    window.removeEventListener('touchmove', this.boundMouseLeaveHandler, false);
+  };
+
+  /**
+   * Initialize element.
+   */
+  MaterialTooltip.prototype.init = function() {
+
+    if (this.element_) {
+      var forElId = this.element_.getAttribute('for');
+
+      if (forElId) {
+        this.forElement_ = document.getElementById(forElId);
       }
 
-      this.boundMouseEnterHandler = this.handleMouseEnter_.bind(this);
-      this.boundMouseLeaveHandler = this.handleMouseLeave_.bind(this);
-      this.forElement_.addEventListener('mouseenter', this.boundMouseEnterHandler,
-          false);
-      this.forElement_.addEventListener('click', this.boundMouseEnterHandler,
-          false);
-      this.forElement_.addEventListener('blur', this.boundMouseLeaveHandler);
-      this.forElement_.addEventListener('touchstart', this.boundMouseEnterHandler,
-          false);
-      this.forElement_.addEventListener('mouseleave', this.boundMouseLeaveHandler);
+      if (this.forElement_) {
+        // Tabindex needs to be set for `blur` events to be emitted
+        if (!this.forElement_.getAttribute('tabindex')) {
+          this.forElement_.setAttribute('tabindex', '0');
+        }
+
+        this.boundMouseEnterHandler = this.handleMouseEnter_.bind(this);
+        this.boundMouseLeaveHandler = this.handleMouseLeave_.bind(this);
+        this.forElement_.addEventListener('mouseenter', this.boundMouseEnterHandler,
+            false);
+        this.forElement_.addEventListener('click', this.boundMouseEnterHandler,
+            false);
+        this.forElement_.addEventListener('blur', this.boundMouseLeaveHandler);
+        this.forElement_.addEventListener('touchstart', this.boundMouseEnterHandler,
+            false);
+        this.forElement_.addEventListener('mouseleave', this.boundMouseLeaveHandler);
+      }
     }
-  }
-};
+  };
 
-/*
-* Downgrade the component
-*/
-MaterialTooltip.prototype.mdlDowngrade_ = function() {
-  'use strict';
-  if (this.forElement_) {
-    this.forElement_.removeEventListener('mouseenter', this.boundMouseEnterHandler, false);
-    this.forElement_.removeEventListener('click', this.boundMouseEnterHandler, false);
-    this.forElement_.removeEventListener('touchstart', this.boundMouseEnterHandler, false);
-    this.forElement_.removeEventListener('mouseleave', this.boundMouseLeaveHandler);
-  }
-};
+  /**
+   * Downgrade the component
+   *
+   * @private
+   */
+  MaterialTooltip.prototype.mdlDowngrade_ = function() {
+    if (this.forElement_) {
+      this.forElement_.removeEventListener('mouseenter', this.boundMouseEnterHandler, false);
+      this.forElement_.removeEventListener('click', this.boundMouseEnterHandler, false);
+      this.forElement_.removeEventListener('touchstart', this.boundMouseEnterHandler, false);
+      this.forElement_.removeEventListener('mouseleave', this.boundMouseLeaveHandler);
+    }
+  };
 
-// The component registers itself. It can assume componentHandler is available
-// in the global scope.
-componentHandler.register({
-  constructor: MaterialTooltip,
-  classAsString: 'MaterialTooltip',
-  cssClass: 'mdl-tooltip'
-});
+  // The component registers itself. It can assume componentHandler is available
+  // in the global scope.
+  componentHandler.register({
+    constructor: MaterialTooltip,
+    classAsString: 'MaterialTooltip',
+    cssClass: 'mdl-tooltip'
+  });
+})();