diff --git a/lib/mixins/properties-changed.html b/lib/mixins/properties-changed.html
index 6269babe2f..fd6fbc9630 100644
--- a/lib/mixins/properties-changed.html
+++ b/lib/mixins/properties-changed.html
@@ -20,39 +20,6 @@
     /** @const {!AsyncInterface} */
     const microtask = Polymer.Async.microTask;
 
-    /**
-     * Returns the map matching attribute names to properties. This map is
-     * used in `propertyNameForAttribute` which locks property names and
-     * attribute names together using this data.
-     *
-     * @private
-     * @param {PropertiesChangedConstructor} constructor PropertiesChanged
-     * constructor
-     * @return {Object} Object mapping property names to attributes.
-     */
-     function getAttributeToPropertyMap(constructor) {
-      return constructor.__attributeToPropertyMap;
-    }
-
-    /**
-     * Adds to the `attributeToPropertyMap` for the given class. A key for the
-     * attribute discovered via `attributeNameForProperty` points to the
-     * given property name. This map is used in `propertyNameForAttribute`.
-     *
-     * @private
-     * @param {PropertiesChangedConstructor} constructor PropertiesChanged
-     * constructor
-     * @param {string} property Property name.
-     */
-    function addToAttributeToPropertyMap(constructor, property) {
-      if (!constructor.hasOwnProperty(JSCompiler_renameProperty(
-        '__attributeToPropertyMap', constructor))) {
-        constructor.__attributeToPropertyMap = {};
-      }
-      const attr = constructor.attributeNameForProperty(property);
-      constructor.__attributeToPropertyMap[attr] = property;
-    }
-
     /**
      * Element class mixin that provides basic meta-programming for creating one
      * or more property accessors (getter/setter pair) that enqueue an async
@@ -112,7 +79,7 @@
          * @protected
          */
         static propertyNameForAttribute(attribute) {
-          const map = getAttributeToPropertyMap(this);
+          const map = this.prototype.__dataAttributes;
           return map && map[attribute] || attribute;
         }
 
@@ -157,9 +124,13 @@
           if (!this.hasOwnProperty('__dataHasAccessor')) {
             this.__dataHasAccessor = Object.assign({}, this.__dataHasAccessor);
           }
+          if (!this.hasOwnProperty('__dataAttributes')) {
+            this.__dataAttributes = Object.assign({}, this.__dataAttributes);
+          }
           if (!this.__dataHasAccessor[property]) {
             this.__dataHasAccessor[property] = true;
-            addToAttributeToPropertyMap(this.constructor, property);
+            const attr = this.constructor.attributeNameForProperty(property);
+            this.__dataAttributes[attr] = property;
             this._definePropertyAccessor(property, readOnly);
           }
         }
diff --git a/test/unit/polymer.properties-element.html b/test/unit/polymer.properties-element.html
index ed89ecf0dd..2f393886a7 100644
--- a/test/unit/polymer.properties-element.html
+++ b/test/unit/polymer.properties-element.html
@@ -100,7 +100,8 @@
 
         static get properties() {
           return {
-            prop2: String
+            prop2: String,
+            camelCase2: String
           };
         }
 
@@ -208,7 +209,7 @@
 
   <test-fixture id="sub-element-attr">
     <template>
-      <sub-element prop="attr" prop2="attr" custom-observed-attr="custom"></sub-element>
+      <sub-element prop="attr" prop2="attr" camelCase="camelCase" camelCase2="camelCase2" custom-observed-attr="custom"></sub-element>
     </template>
   </test-fixture>
 
@@ -326,7 +327,9 @@
       var fixtureEl = fixture('sub-element-attr');
       assert.equal(fixtureEl.prop, 'attr');
       assert.equal(fixtureEl.prop2, 'attr');
-      assert.equal(fixtureEl._callAttributeChangedCallback, 3);
+      assert.equal(fixtureEl.camelCase, 'camelCase');
+      assert.equal(fixtureEl.camelCase2, 'camelCase2');
+      assert.equal(fixtureEl._callAttributeChangedCallback, 5);
     });
 
   });