diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index b01d1bcbd..b8545df90 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "taskchampion-lib"
 version = "0.1.0"
-edition = "2021"
+edition = "2018"
 build = "build.rs"
 
 [lib]