diff --git a/lib/arena/Cargo.toml b/lib/arena/Cargo.toml
index f41793092c..39b005d094 100644
--- a/lib/arena/Cargo.toml
+++ b/lib/arena/Cargo.toml
@@ -7,4 +7,4 @@ repository = "https://github.com/rust-analyzer/rust-analyzer"
 documentation = "https://docs.rs/la-arena"
 categories = ["data-structures", "memory-management", "rust-patterns"]
 edition = "2021"
-rust-version = "1.57"
+rust-version = "1.56"