diff --git a/src/gtk320/widgets/_base.scss b/src/gtk320/widgets/_base.scss
--- a/src/gtk320/widgets/_base.scss
+++ b/src/gtk320/widgets/_base.scss
@@ -9,19 +9,12 @@
   -GtkToolButton-icon-spacing: 4;
   -GtkTextView-error-underline-color: $error_color;
 
-  -GtkButton-child-displacement-x: 0;
-  -GtkButton-child-displacement-y: 0;
-
-  -GtkCheckButton-indicator-size: 18;
-  -GtkCheckMenuItem-indicator-size: 18;
-
   // The size for scrollbars. The slider is 2px smaller, but we keep it
   // up so that the whole area is sensitive to button presses for the
   // slider. The stepper button is larger in both directions, the slider
   // only in the width
 
   -GtkScrolledWindow-scrollbar-spacing: 0;
-  -GtkScrolledWindow-scrollbars-within-bevel: 0;
 
   -GtkScrolled-window-overlay-scrolling: FALSE;
 
@@ -37,8 +30,6 @@
   -GtkDialog-button-spacing: 4;
   -GtkDialog-action-area-border: 0;
 
-  -GtkStatusbar-shadow-type: none;
-
   outline-width: 0px;
 }
 
@@ -100,7 +91,7 @@
     color: backdrop(v_color(text));
     background-color: backdrop(v_color(normal));
   }
-  
+
   &:disabled {
     color: insensitive(v_color(text));
   }
@@ -223,7 +214,7 @@
   }
 }
 
-%osd, 
+%osd,
 .osd {
   color: w_color(text);
   border: 1px solid $border_color;
diff --git a/src/gtk320/widgets/_treeview.scss b/src/gtk320/widgets/_treeview.scss
--- a/src/gtk320/widgets/_treeview.scss
+++ b/src/gtk320/widgets/_treeview.scss
@@ -55,6 +55,9 @@
   }
 
   &.expander {
+    // GtkTreeView uses the larger of the expander’s min-width and min-height
+    min-width: 16px;
+    min-height: 16px;
     -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
     color: v_color(text);
     &:dir(rtl) { -gtk-icon-source: -gtk-icontheme('pan-start-symbolic'); };