diff --git a/.github/workflows/unit.yaml b/.github/workflows/unit.yaml
index b709cd4b..2ffed4e9 100644
--- a/.github/workflows/unit.yaml
+++ b/.github/workflows/unit.yaml
@@ -21,7 +21,7 @@ jobs:
           submodules: 'recursive'
 
       - name: Install toolchain
-        uses: dtolnay/rust-toolchain@stable
+        uses: dtolnay/rust-toolchain@1.79.0
         with:
           components: llvm-tools-preview