diff --git a/lib/mixins/property-accessors.html b/lib/mixins/property-accessors.html
index e8e0b32152..9682e3222c 100644
--- a/lib/mixins/property-accessors.html
+++ b/lib/mixins/property-accessors.html
@@ -265,6 +265,9 @@
               console.warn(`Polymer::Attributes: couldn't decode Array as JSON: ${value}`);
             }
             break;
+          case Date:
+            outValue = new Date(value);
+            break;
           default:
             outValue = super._deserializeValue(value, type);
             break;