diff --git a/assertions/Cargo.toml b/assertions/Cargo.toml
index 6d40a52159..60b1c5e59d 100644
--- a/assertions/Cargo.toml
+++ b/assertions/Cargo.toml
@@ -2,6 +2,7 @@
 name = "assertions"
 version = "0.1.0"
 authors = ["The Chromium OS Authors"]
+edition = "2018"
 include = ["src/**/*", "Cargo.toml"]
 
 [workspace]