diff --git a/lcl/interfaces/gtk2/gtk2themes.pas b/lcl/interfaces/gtk2/gtk2themes.pas
index 0a0bd1f90c..5fa9ef10e6 100644
--- a/lcl/interfaces/gtk2/gtk2themes.pas
+++ b/lcl/interfaces/gtk2/gtk2themes.pas
@@ -560,14 +560,23 @@ function TGtk2ThemeServices.GetDetailSize(Details: TThemedElementDetails): TSize
 var
   AValue: TGValue;
 begin
-  if (Details.Element = teTreeView) and (Details.Part in [TVP_GLYPH, TVP_HOTGLYPH]) then
+  if (Details.Element = teTreeView) and (Byte(Details.Part) in [TVP_GLYPH, TVP_HOTGLYPH]) then
   begin
     FillChar(AValue{%H-}, SizeOf(AValue), 0);
     g_value_init(@AValue, G_TYPE_INT);
     gtk_widget_style_get_property(GetStyleWidget(lgsTreeView), 'expander-size', @AValue);
     Result := Size(AValue.data[0].v_int, AValue.data[0].v_int);
-  end
-  else
+  end else
+  if (Details.Element = teButton) and (Byte(Details.Part) in [BP_CHECKBOX, BP_RADIOBUTTON]) then
+  begin
+    FillChar(AValue{%H-}, SizeOf(AValue), 0);
+    g_value_init(@AValue, G_TYPE_INT);
+    if Details.Part = BP_CHECKBOX then
+      gtk_widget_style_get_property(GetStyleWidget(lgsCheckbox),'indicator-size', @AValue)
+    else
+      gtk_widget_style_get_property(GetStyleWidget(lgsRadioButton),'indicator-size', @AValue);
+    Result := Size(AValue.data[0].v_int, AValue.data[0].v_int);
+  end else
     Result := GetBaseDetailsSize(Details);
 end;