diff --git a/aio/package.json b/aio/package.json
index 855821ef5a..2e3810f776 100644
--- a/aio/package.json
+++ b/aio/package.json
@@ -107,7 +107,7 @@
     "cross-spawn": "^5.1.0",
     "css-selector-parser": "^1.3.0",
     "dgeni": "^0.4.7",
-    "dgeni-packages": "0.24.1",
+    "dgeni-packages": "^0.24.2",
     "entities": "^1.1.1",
     "eslint": "^3.19.0",
     "eslint-plugin-jasmine": "^2.2.0",
diff --git a/aio/tools/transforms/templates/api/lib/paramList.html b/aio/tools/transforms/templates/api/lib/paramList.html
index b13e851ce6..3f5ac09c82 100644
--- a/aio/tools/transforms/templates/api/lib/paramList.html
+++ b/aio/tools/transforms/templates/api/lib/paramList.html
@@ -19,9 +19,13 @@
     <tr class="{$ parameterClass $}">
       <td class="param-name"><a id="{$ parameter.anchor $}"></a>{$ parameter.name $}</td>
       <td class="param-description">
-        {% if parameter.description | trim %}{$ parameter.description | marked $}
+      {% marked %}
+        {% if parameter.isOptional %}Optional.{% endif %}
+
+        {% if parameter.description | trim %}{$ parameter.description $}
         {% elseif parameter.type %}<code>{$ parameter.type $}</code>
         {% endif %}
+      {% endmarked %}
       </td>
     </tr>{% endfor %}
   </tbody>
diff --git a/aio/yarn.lock b/aio/yarn.lock
index 409398dfce..bda10a5322 100644
--- a/aio/yarn.lock
+++ b/aio/yarn.lock
@@ -2312,9 +2312,9 @@ devtools-timeline-model@1.1.6:
     chrome-devtools-frontend "1.0.401423"
     resolve "1.1.7"
 
-dgeni-packages@0.24.1:
-  version "0.24.1"
-  resolved "https://registry.yarnpkg.com/dgeni-packages/-/dgeni-packages-0.24.1.tgz#e3e99eb82615b30a9e43fe1a9bb9911ff6bbf913"
+dgeni-packages@^0.24.2:
+  version "0.24.2"
+  resolved "https://registry.yarnpkg.com/dgeni-packages/-/dgeni-packages-0.24.2.tgz#88e75f0f4cfd135a2c6c8ec431b66f32d63760d2"
   dependencies:
     canonical-path "0.0.2"
     catharsis "^0.8.1"