diff --git a/lib/mixins/dir-mixin.js b/lib/mixins/dir-mixin.js
index 7208e2eb73..7d48fc4ff9 100644
--- a/lib/mixins/dir-mixin.js
+++ b/lib/mixins/dir-mixin.js
@@ -1,4 +1,5 @@
 /**
+ * @suppress {checkPrototypalTypes}
  * @license Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
  * This code may only be used under the BSD style license found at
  * http://polymer.github.io/LICENSE.txt The complete set of authors may be found
@@ -6,7 +7,6 @@
  * be found at http://polymer.github.io/CONTRIBUTORS.txt Code distributed by
  * Google as part of the polymer project is also subject to an additional IP
  * rights grant found at http://polymer.github.io/PATENTS.txt
- * @suppress {checkPrototypalTypes}
  */
 import { PropertyAccessors } from './property-accessors.js';
 
diff --git a/lib/mixins/disable-upgrade-mixin.js b/lib/mixins/disable-upgrade-mixin.js
index d04ee27a4b..c363259ab5 100644
--- a/lib/mixins/disable-upgrade-mixin.js
+++ b/lib/mixins/disable-upgrade-mixin.js
@@ -1,4 +1,5 @@
 /**
+ * @suppress {checkPrototypalTypes}
  * @license Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
  * This code may only be used under the BSD style license found at
  * http://polymer.github.io/LICENSE.txt The complete set of authors may be found
@@ -6,7 +7,6 @@
  * be found at http://polymer.github.io/CONTRIBUTORS.txt Code distributed by
  * Google as part of the polymer project is also subject to an additional IP
  * rights grant found at http://polymer.github.io/PATENTS.txt
- * @suppress {checkPrototypalTypes}
  */
 import { ElementMixin } from './element-mixin.js';
 
diff --git a/lib/mixins/element-mixin.js b/lib/mixins/element-mixin.js
index 84399ba333..06fea1a65e 100644
--- a/lib/mixins/element-mixin.js
+++ b/lib/mixins/element-mixin.js
@@ -1,4 +1,5 @@
 /**
+ * @suppress {checkPrototypalTypes}
  * @license Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
  * This code may only be used under the BSD style license found at
  * http://polymer.github.io/LICENSE.txt The complete set of authors may be found
@@ -6,7 +7,6 @@
  * be found at http://polymer.github.io/CONTRIBUTORS.txt Code distributed by
  * Google as part of the polymer project is also subject to an additional IP
  * rights grant found at http://polymer.github.io/PATENTS.txt
- * @suppress {checkPrototypalTypes}
  */
 import '../utils/boot.js';
 
diff --git a/lib/mixins/property-effects.js b/lib/mixins/property-effects.js
index ec0c174316..daa371f496 100644
--- a/lib/mixins/property-effects.js
+++ b/lib/mixins/property-effects.js
@@ -1,4 +1,5 @@
 /**
+ * @suppress {checkPrototypalTypes}
  * @license Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
  * This code may only be used under the BSD style license found at
  * http://polymer.github.io/LICENSE.txt The complete set of authors may be found
@@ -6,7 +7,6 @@
  * be found at http://polymer.github.io/CONTRIBUTORS.txt Code distributed by
  * Google as part of the polymer project is also subject to an additional IP
  * rights grant found at http://polymer.github.io/PATENTS.txt
- * @suppress {checkPrototypalTypes}
  */
 
 import '../utils/boot.js';