diff --git a/src/generic/colrdlgg.cpp b/src/generic/colrdlgg.cpp
index 5843141cab..d99432194e 100644
--- a/src/generic/colrdlgg.cpp
+++ b/src/generic/colrdlgg.cpp
@@ -254,7 +254,7 @@ void wxGenericColourDialog::CreateWidgets(void)
   blueSlider = new wxSlider(this, wxID_BLUE_SLIDER, 0, 0, 255,
    wxPoint(sliderX + 2*sliderSpacing, 10), wxSize(-1, sliderHeight), wxVERTICAL|wxSL_LABELS);
 
-  SetClientSize(sliderX + 3*sliderSpacing, buttonY + 40);
+  SetClientSize(sliderX + 3*sliderSpacing, buttonY + bh + 20);
   okButton->SetDefault();
 
   Centre(wxBOTH);