diff --git a/docs/reference/gtk/css-properties.md b/docs/reference/gtk/css-properties.md
index 41178ff725..d85f872412 100644
--- a/docs/reference/gtk/css-properties.md
+++ b/docs/reference/gtk/css-properties.md
@@ -21,7 +21,7 @@ Percentage
 : %, calc()
 
 Angle
-: deg, grad, turn, calc()
+: deg, rad, grad, turn, calc()
 
 Time
 : s, ms, calc()