--- a/rust/chg/Cargo.toml	Thu Apr 09 16:06:03 2020 +0530
+++ b/rust/chg/Cargo.toml	Fri Apr 10 21:35:16 2020 +0900
@@ -4,6 +4,7 @@
 authors = ["Yuya Nishihara <yuya@tcha.org>"]
 description = "Client for Mercurial command server with cHg extension"
 license = "GPL-2.0+"
+edition = "2018"
 
 [dependencies]
 bytes = "0.4"