diff --git a/src/Pass/PinterestTagTransformPass.php b/src/Pass/PinterestTagTransformPass.php
index 30827311..51a8a38d 100644
--- a/src/Pass/PinterestTagTransformPass.php
+++ b/src/Pass/PinterestTagTransformPass.php
@@ -93,13 +93,21 @@ protected function setPinterestDimensionsFrom(DOMQuery $el, DOMQuery $new_el)
 
         $width = $el->attr('width');
         $height = $el->attr('height');
+
+        if (!empty($height) && empty($width)) {
+            $width = 'auto';
+        }
+
         $hw_available = !empty($width) && !empty($height);
         $new_el->attr('data-pin-width', $pin_width);
         if ($hw_available) {
             $new_el->attr('width', $width);
             $new_el->attr('height', $height);
-        } else {
+            $new_el->attr('layout', $width == 'auto' ? 'fixed-height' : 'fixed');
+        }
+        else {
             $new_el->attr($dimensions[$pin_width]);
+            $new_el->attr('layout', 'responsive');
         }
     }
 }
diff --git a/tests/test-data/fragment-html/pinterest-fragment.html.out b/tests/test-data/fragment-html/pinterest-fragment.html.out
index 8aeab260..fd5b62a7 100644
--- a/tests/test-data/fragment-html/pinterest-fragment.html.out
+++ b/tests/test-data/fragment-html/pinterest-fragment.html.out
@@ -1,4 +1,4 @@
-<amp-pinterest data-url="https://www.pinterest.com/pin/99360735500167749/" data-do="embedPin" data-pin-width="medium" width="345" height="426"></amp-pinterest>
+<amp-pinterest data-url="https://www.pinterest.com/pin/99360735500167749/" data-do="embedPin" data-pin-width="medium" width="345" height="426" layout="responsive"></amp-pinterest>
 
 
 ORIGINAL HTML