diff --git a/demos/gtk-demo/markup.txt b/demos/gtk-demo/markup.txt
index c850fd8c0b..9e42a399a6 100644
--- a/demos/gtk-demo/markup.txt
+++ b/demos/gtk-demo/markup.txt
@@ -18,3 +18,6 @@ Shortcuts: Monospace – Bold – Italic – BigA hyphenation algorithm is a set of rules, especially one codified for implementation in a computer program, that decides at which points a word can be broken over two lines with a hyphen. For example, a hyphenation algorithm might decide that impeachment can be broken as impeach‧ment or im‧peachment but not impe‧achment.
one/two three/four five/six seven/eight nine/ten
+
+Line height: This is an example of widely spaced text. It was achieved by setting the line-height factor to 1.33. You can set the line-height factor to any value between 0 and 10.
+Note that the line height affects the spacing between paragraphs as well as between the wrapped lines inside a paragraph.