diff --git a/res/css/views/elements/_ImageView.scss b/res/css/views/elements/_ImageView.scss
index 9b77f70262..45968ddaa5 100644
--- a/res/css/views/elements/_ImageView.scss
+++ b/res/css/views/elements/_ImageView.scss
@@ -131,7 +131,7 @@ limitations under the License.
 
 .mx_ImageView_button_close {
     border-radius: 100%;
-    background: #21262C;
+    background: #21262c;
     &::before {
         width: 32px;
         height: 32px;