diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6fc2453..848870e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -148,7 +148,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Install Rust toolchain (pinned MSRV)
-        uses: dtolnay/rust-toolchain@1.90
+        uses: dtolnay/rust-toolchain@1.100
 
       # Distinct cache key: 1.90 build artifacts are not interchangeable with the
       # stable debug/release caches the other jobs share.