diff --git a/doc/docs.md b/doc/docs.md
index 3ad48dc8d2..e97a7591d7 100644
--- a/doc/docs.md
+++ b/doc/docs.md
@@ -1151,7 +1151,7 @@ struct CallExpr {
 	...
 }
 
-fn (p mut Parser) expr(precedence int) Expr {
+fn (mut p Parser) expr(precedence int) Expr {
 	match p.tok {
 		.key_if { return IfExpr{} }
 		...
@@ -1161,7 +1161,7 @@ fn (p mut Parser) expr(precedence int) Expr {
 
 fn gen(expr Expr) {
 	match expr {
-		IfExpr { gen_if(it) }
+		IfExpr { gen_if(expr) } // `expr` is cast to the matched type automatically
 		...
 	}
 }