diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1532a7a..4e6826b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -17,7 +17,7 @@ jobs:
       - name: Install apt-get
         run: sudo apt-get install -y clang llvm
       - name: Install latest nightly
-        uses: dtolnay/rust-toolchain@v1
+        uses: dtolnay/rust-toolchain@888c2e1ea69ab0d4330cbf0af1ecc7b68f368cc1 # v1
         with:
             toolchain: nightly
             components: rustfmt, clippy