diff --git a/themes/intotheeast/blueprints/trip.yaml b/themes/intotheeast/blueprints/trip.yaml
index 6e22b60..f913581 100644
--- a/themes/intotheeast/blueprints/trip.yaml
+++ b/themes/intotheeast/blueprints/trip.yaml
@@ -39,6 +39,7 @@ form:
 
             header.cover_image:
               type: pagemediaselect
+              accept: ['.jpg', '.jpeg', '.png', '.webp', '.gif']
               label: 'Cover Image'
               help: 'Pick from images uploaded to this trip page. Shown on the trips listing and the trip-page banner. Falls back to the first journal entry photo if left unset.'
 
diff --git a/themes/intotheeast/templates/macros/cover.html.twig b/themes/intotheeast/templates/macros/cover.html.twig
index bd0ed64..8b7b3e3 100644
--- a/themes/intotheeast/templates/macros/cover.html.twig
+++ b/themes/intotheeast/templates/macros/cover.html.twig
@@ -10,7 +10,10 @@
     3. else nothing.
   A set-but-missing cover_image (deleted/moved file) is `is not defined` in
   page media, so it falls through to the auto-pick rather than rendering a
-  broken image (R11).
+  broken image (R11). Resolution matches against `media.images` (not all
+  media), so a non-image selection — e.g. a `.gpx` from the trip page's own
+  media, which the picker used to offer — also falls through instead of
+  routing a non-image Medium into cropResize.
 
   Twig macros can only emit strings — they cannot return a Medium object —
   so resolution and rendering live together in one macro: it emits the
@@ -22,8 +25,8 @@
 #}
 {% macro render(trip_page, alt, w, h, wrapper_class, sizes) %}
 {%- set cover = null -%}
-{%- if trip_page.header.cover_image and trip_page.media[trip_page.header.cover_image] is defined -%}
-    {%- set cover = trip_page.media[trip_page.header.cover_image] -%}
+{%- if trip_page.header.cover_image and trip_page.media.images[trip_page.header.cover_image] is defined -%}
+    {%- set cover = trip_page.media.images[trip_page.header.cover_image] -%}
 {%- else -%}
     {%- set dailies_page = grav.pages.find(trip_page.route ~ '/dailies') -%}
     {%- if dailies_page -%}