diff --git a/Cargo.toml b/Cargo.toml
index 8aa6116..f891979 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,6 +17,7 @@ include = [
     "LICENSE-MIT",
     "LICENSE-APACHE",
 ]
+edition = "2018"
 
 [features]
 default = []