diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 12bd171..032199f 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -106,7 +106,7 @@ jobs:
       - name: Install rust toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: nightly-2024-02-07
+          toolchain: nightly-2024-05-01
           # ^ sync with https://github.com/awslabs/cargo-check-external-types/blob/main/rust-toolchain.toml
       - run: cargo install cargo-check-external-types
       - run: cargo check-external-types