diff --git a/news/181.bugfix b/news/181.bugfix
new file mode 100644
index 0000000..70193a8
--- /dev/null
+++ b/news/181.bugfix
@@ -0,0 +1 @@
+Add nav_title and head_title to the default summary serializer metadata fields. @davisagli
diff --git a/src/plone/volto/summary.py b/src/plone/volto/summary.py
index b2e5dda..0a71a45 100644
--- a/src/plone/volto/summary.py
+++ b/src/plone/volto/summary.py
@@ -6,6 +6,8 @@
 class JSONSummarySerializerMetadata:
     def default_metadata_fields(self):
         return {
+            "head_title",
             "image_field",
             "image_scales",
+            "nav_title",
         }