diff --git a/src/sass/gtk/_common-3.0.scss b/src/sass/gtk/_common-3.0.scss
index a9fba45a..33c3a22d 100644
--- a/src/sass/gtk/_common-3.0.scss
+++ b/src/sass/gtk/_common-3.0.scss
@@ -1494,7 +1494,7 @@ headerbar {
     transition: $backdrop_transition;
     color: transparentize($header_fg, 0.3);
     background-color: $header_bg_backdrop;
-    border-color: if($variant=='light', lighten($header_border, 5%), darken($header_border, 3%));
+    border-bottom: 1px solid if($variant=='light', lighten($header_border, 5%), darken($header_border, 3%));
   }
 
   .title {
@@ -1759,17 +1759,6 @@ headerbar {
     box-shadow: none;
   }
 
-  .maximized & {
-    background-color: $header_bg;
-    border-color: opacify($header_border, 1);
-    box-shadow: none;
-
-    &:backdrop {
-      background-color: $header_bg_backdrop;
-      border-color: if($variant=='light', lighten($header_border, 15%), darken($header_border, 3%));
-    }
-  }
-
   &.default-decoration {
     min-height: $medium_size;
     padding: 0 $container_padding * 2;