diff --git a/cps/templates/image.html b/cps/templates/image.html
index ae57727b..728384a1 100644
--- a/cps/templates/image.html
+++ b/cps/templates/image.html
@@ -16,7 +16,7 @@
     {% set srcset = series|get_series_srcset %}
     <img
         srcset="{{ srcset }}"
-        src="{{ url_for('web.get_series_cover', series_id=series.id, resolution='og', c='month'|cache_timestamp) }}"
+        src="{{ url_for('web.get_series_cover', series_id=series.id, resolution='og', c='day'|cache_timestamp) }}"
         title="{{ title }}"
         alt="{{ book_title }}"
     />