diff --git a/src/tools/rust-analyzer/.github/workflows/ci.yaml b/src/tools/rust-analyzer/.github/workflows/ci.yaml
index c3a5017d72d7..ca7d3058d8f0 100644
--- a/src/tools/rust-analyzer/.github/workflows/ci.yaml
+++ b/src/tools/rust-analyzer/.github/workflows/ci.yaml
@@ -206,8 +206,11 @@ jobs:
 
       - name: Install Rust toolchain
         run: |
-          rustup update --no-self-update nightly
-          rustup default nightly
+          # FIXME: Pin nightly due to a regression in miri on nightly-2026-02-12.
+          # See https://github.com/rust-lang/miri/issues/4855.
+          # Revert to plain `nightly` once this is fixed upstream.
+          rustup toolchain install nightly-2026-02-10
+          rustup default nightly-2026-02-10
           rustup component add miri
 
       # - name: Cache Dependencies