diff --git a/app/static/structure.css b/app/static/structure.css
index b2ef4131..44dd1c0c 100644
--- a/app/static/structure.css
+++ b/app/static/structure.css
@@ -724,6 +724,9 @@ fieldset legend {
 [data-bs-theme=dark] .post_list .post_teaser {
   border-bottom: solid 1px #424549;
 }
+[data-bs-theme=dark] .post_list .post_teaser .thumbnail .fe {
+  background-color: rgba(0, 0, 0, 0.4);
+}
 [data-bs-theme=dark] .comments > .comment {
   border-top-color: #424549;
 }
diff --git a/app/static/structure.scss b/app/static/structure.scss
index 4c03400d..3dec87d3 100644
--- a/app/static/structure.scss
+++ b/app/static/structure.scss
@@ -356,6 +356,9 @@ nav, etc which are used site-wide */
 [data-bs-theme=dark] {
   .post_list .post_teaser {
     border-bottom: solid 1px $super-dark-grey;
+    .thumbnail .fe {
+      background-color: rgba(0,0,0,0.4);
+    }
   }
 
   .comments > .comment {