diff --git a/src/_sass/_variables.scss b/src/_sass/_variables.scss
index e8e808e..68ca7ff 100644
--- a/src/_sass/_variables.scss
+++ b/src/_sass/_variables.scss
@@ -21,7 +21,7 @@ $menuitem-size: if($compact == 'false', 28px, 24px);
 //
 
 $window-radius: $default_corner + $space-size;
-$corner-radius: if($compact == 'false', $default_corner, $default_corner - 2px);
+$corner-radius: if($compact == 'false', $default_corner, max(0, $default_corner - 2px));
 $menu-radius: $default_corner / 4 + $space-size + 2px;
 $menuitem-radius: $default_corner / 4 + 2px;
 $circular-radius: 9999px;
diff --git a/src/_sass/gtk/apps/_budgie.scss b/src/_sass/gtk/apps/_budgie.scss
index ff60df1..5bfd813 100644
--- a/src/_sass/gtk/apps/_budgie.scss
+++ b/src/_sass/gtk/apps/_budgie.scss
@@ -53,11 +53,11 @@
 
     button {
       @extend %button-flat-simple;
-      border-radius: $corner-radius - $space-size;
+      border-radius: max(0, $corner-radius - $space-size);
     }
   }
 
-  calendar:not(.header) { border-radius: $corner-radius - $space-size; }
+  calendar:not(.header) { border-radius: max(0, $corner-radius - $space-size); }
 
   scrolledwindow.sidebar.categories { // AppMenu
     background-color: $fill;
@@ -108,14 +108,14 @@
     }
   }
 
-  button { border-radius: $corner-radius - $space-size; }
+  button { border-radius: max(0, $corner-radius - $space-size); }
 
   button.flat:not(.image-button) {
     min-height: $menuitem-size;
     padding: 0 8px;
     color: $text;
     font-weight: normal;
-    border-radius: $corner-radius - $space-size;
+    border-radius: max(0, $corner-radius - $space-size);
 
     &:disabled { color: $text-disabled; }
   }