diff --git a/gtk/resources/theme/Adwaita/_common.scss b/gtk/resources/theme/Adwaita/_common.scss
index 7b7c3595a1..0c50fa31b7 100644
--- a/gtk/resources/theme/Adwaita/_common.scss
+++ b/gtk/resources/theme/Adwaita/_common.scss
@@ -1127,6 +1127,7 @@ column-header {
 }
 
 .scrollbars-junction { // the small square between two scrollbars
+  border-style: none;
   background-color: darken($bg_color, 5%);
   &:backdrop { background-color: transparent; }
 }
diff --git a/gtk/resources/theme/Adwaita/gtk-contained-dark.css b/gtk/resources/theme/Adwaita/gtk-contained-dark.css
index 39ee8956e3..3b6ccc6047 100644
--- a/gtk/resources/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/resources/theme/Adwaita/gtk-contained-dark.css
@@ -1302,6 +1302,7 @@ column-header .button, column-header .button:hover, column-header .button:active
         background-color: #215d9c; }
 
 .scrollbars-junction, .scrollbar.trough {
+  border-style: none;
   background-color: #2d3232; }
   .scrollbars-junction:backdrop, .scrollbar.trough:backdrop {
     background-color: transparent; }
diff --git a/gtk/resources/theme/Adwaita/gtk-contained.css b/gtk/resources/theme/Adwaita/gtk-contained.css
index 5f0b8ffc7f..6123cefed2 100644
--- a/gtk/resources/theme/Adwaita/gtk-contained.css
+++ b/gtk/resources/theme/Adwaita/gtk-contained.css
@@ -1302,6 +1302,7 @@ column-header .button, column-header .button:hover, column-header .button:active
         background-color: #4a90d9; }
 
 .scrollbars-junction, .scrollbar.trough {
+  border-style: none;
   background-color: #e0e0e0; }
   .scrollbars-junction:backdrop, .scrollbar.trough:backdrop {
     background-color: transparent; }