diff --git a/docs/tut/crash-course.md b/docs/tut/crash-course.md
index 5de9299..a7dd230 100644
--- a/docs/tut/crash-course.md
+++ b/docs/tut/crash-course.md
@@ -141,7 +141,7 @@ local derive = vide.derive
 ```
 
 ```lua
-local count = wrap(0)
+local count = source(0)
 
 local factorial = derive(function()
     local n = 1