diff --git a/Cargo.toml b/Cargo.toml
index a9e1a5a..ca54639 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,7 @@ categories = ["embedded", "encoding", "no-std"]
 keywords = ["serde", "cbor", "rust", "no-std"]
 repository = "https://github.com/nickray/serde-indexed"
 readme = "README.md"
-edition = "2018"
+edition = "2021"
 
 [lib]
 proc-macro = true