diff --git a/docs/src/01_manual/04_widgets.md b/docs/src/01_manual/04_widgets.md
index 199e936..1599445 100644
--- a/docs/src/01_manual/04_widgets.md
+++ b/docs/src/01_manual/04_widgets.md
@@ -138,8 +138,8 @@ set_margin_top!(widget, 10)
 set_margin_bottom!(widget, 10)
 
 # equivalent to
-set_margin_horizontal(widget, 10)
-set_margin_vertical(widget, 10)
+set_margin_horizontal!(widget, 10)
+set_margin_vertical!(widget, 10)
 
 # equivalent to
 set_margin!(widget, 10)