diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index e237a635eb..15dcb92682 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -351,11 +351,12 @@ BufferView::~BufferView()
 
 int BufferView::rightMargin() const
 {
+	// The value used to be hardcoded to 10, which is 2.5mm at 100dpi
+	int const default_margin = Length(2.5, Length::MM).inPixels(0);
 	// The additional test for the case the outliner is opened.
-	if (!full_screen_ ||
-		!lyxrc.full_screen_limit ||
-		width_ < lyxrc.full_screen_width + 20)
-			return 10;
+	if (!full_screen_ || !lyxrc.full_screen_limit
+	    || width_ < lyxrc.full_screen_width + 2 * default_margin)
+		return default_margin;
 
 	return (width_ - lyxrc.full_screen_width) / 2;
 }