diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9496f9c..dbf0280 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,8 +35,15 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Install Rust toolchain
-        uses: dtolnay/rust-toolchain@1.84.1
+        # Pin the action to its major-version tag and pass the Rust toolchain version
+        # explicitly via `with.toolchain`. Decouples action upgrades from toolchain
+        # version pinning. The explicit `toolchain: 1.84.1` input matches the project's
+        # already-pinned `rust-toolchain.toml`, so rustup derives the per-host triple
+        # correctly and `cargo install` no longer resolves against a stale channel name.
+        # See Octo-Protocol-org/Octo-Protocol#33.
+        uses: dtolnay/rust-toolchain@v1
         with:
+          toolchain: 1.84.1
           components: rustfmt, clippy
 
       - name: Cache cargo
@@ -77,3 +84,10 @@ jobs:
       - uses: gitleaks/gitleaks-action@v2
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+# No-op trigger: re-run CI on PR #35 to verify whether the failure mode persists across two clean runs.
+# Useful for distinguishing a transient cache issue from a real toolchain-action regression.
+
+# No-op trigger: re-run CI on PR #35 to verify whether the failure mode persists
+# across two clean runs. Useful for distinguishing a transient cache issue from a real
+# toolchain-action regression. No semantic change.