diff --git a/src/tools/miri/.github/workflows/ci.yml b/src/tools/miri/.github/workflows/ci.yml
index 3bc4163ab5246..fc4e484fa3898 100644
--- a/src/tools/miri/.github/workflows/ci.yml
+++ b/src/tools/miri/.github/workflows/ci.yml
@@ -33,50 +33,7 @@ jobs:
       HOST_TARGET: ${{ matrix.host_target }}
     steps:
       - uses: actions/checkout@v4
-
-      - name: Show Rust version (stable toolchain)
-        run: |
-          rustup show
-          rustc -Vv
-          cargo -V
-
-      # Cache the global cargo directory, but NOT the local `target` directory which
-      # we cannot reuse anyway when the nightly changes (and it grows quite large
-      # over time).
-      - name: Add cache for cargo
-        id: cache
-        uses: actions/cache@v4
-        with:
-          path: |
-            # Taken from <https://doc.rust-lang.org/nightly/cargo/guide/cargo-home.html#caching-the-cargo-home-in-ci>.
-            # Cache package/registry information
-            ~/.cargo/registry/index
-            ~/.cargo/registry/cache
-            ~/.cargo/git/db
-            # Cache installed binaries
-            ~/.cargo/bin
-            ~/.cargo/.crates.toml
-            ~/.cargo/.crates2.json
-          key: cargo-${{ runner.os }}-reset20240425-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: cargo-${{ runner.os }}-reset20240425
-
-      - name: Install tools
-        if: steps.cache.outputs.cache-hit != 'true'
-        run: cargo install -f rustup-toolchain-install-master hyperfine
-
-      - name: Install miri toolchain
-        run: |
-          if [[ ${{ github.event_name }} == 'schedule' ]]; then
-            echo "Building against latest rustc git version"
-            git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1 > rust-version
-          fi
-          ./miri toolchain --host ${{ matrix.host_target }}
-
-      - name: Show Rust version (miri toolchain)
-        run: |
-          rustup show
-          rustc -Vv
-          cargo -V
+      - uses: ./.github/workflows/setup
 
       # The `style` job only runs on Linux; this makes sure the Windows-host-specific
       # code is also covered by clippy.
@@ -92,47 +49,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-
-      # This is exactly duplicated from above. GHA is pretty terrible when it comes
-      # to avoiding code duplication.
-
-      # Cache the global cargo directory, but NOT the local `target` directory which
-      # we cannot reuse anyway when the nightly changes (and it grows quite large
-      # over time).
-      - name: Add cache for cargo
-        id: cache
-        uses: actions/cache@v4
-        with:
-          path: |
-            # Taken from <https://doc.rust-lang.org/nightly/cargo/guide/cargo-home.html#caching-the-cargo-home-in-ci>.
-            # Cache package/registry information
-            ~/.cargo/registry/index
-            ~/.cargo/registry/cache
-            ~/.cargo/git/db
-            # Cache installed binaries
-            ~/.cargo/bin
-            ~/.cargo/.crates.toml
-            ~/.cargo/.crates2.json
-          key: cargo-${{ runner.os }}-reset20240331-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: cargo-${{ runner.os }}-reset20240331
-
-      - name: Install rustup-toolchain-install-master
-        if: steps.cache.outputs.cache-hit != 'true'
-        run: cargo install -f rustup-toolchain-install-master
-
-      - name: Install "master" toolchain
-        run: |
-          if [[ ${{ github.event_name }} == 'schedule' ]]; then
-            echo "Building against latest rustc git version"
-            git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1 > rust-version
-          fi
-          ./miri toolchain
-
-      - name: Show Rust version
-        run: |
-          rustup show
-          rustc -Vv
-          cargo -V
+      - uses: ./.github/workflows/setup
 
       - name: rustfmt
         run: ./miri fmt --check
diff --git a/src/tools/miri/.github/workflows/setup/action.yml b/src/tools/miri/.github/workflows/setup/action.yml
new file mode 100644
index 0000000000000..8f54b5b8d81a9
--- /dev/null
+++ b/src/tools/miri/.github/workflows/setup/action.yml
@@ -0,0 +1,52 @@
+name: "Miri CI setup"
+description: "Sets up Miri CI"
+runs:
+  using: "composite"
+  steps:
+      - name: Show Rust version (stable toolchain)
+        run: |
+          rustup show
+          rustc -Vv
+          cargo -V
+        shell: bash
+
+      # Cache the global cargo directory, but NOT the local `target` directory which
+      # we cannot reuse anyway when the nightly changes (and it grows quite large
+      # over time).
+      - name: Add cache for cargo
+        id: cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            # Taken from <https://doc.rust-lang.org/nightly/cargo/guide/cargo-home.html#caching-the-cargo-home-in-ci>.
+            # Cache package/registry information
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            # Cache installed binaries
+            ~/.cargo/bin
+            ~/.cargo/.crates.toml
+            ~/.cargo/.crates2.json
+          key: cargo-${{ runner.os }}-${{ hashFiles('**/Cargo.lock', '.github/workflows/**/*.yml') }}
+          restore-keys: cargo-${{ runner.os }}
+
+      - name: Install rustup-toolchain-install-master
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: cargo install -f rustup-toolchain-install-master hyperfine
+        shell: bash
+
+      - name: Install "master" toolchain
+        run: |
+          if [[ ${{ github.event_name }} == 'schedule' ]]; then
+            echo "Building against latest rustc git version"
+            git ls-remote https://github.com/rust-lang/rust/ HEAD | cut -f 1 > rust-version
+          fi
+          ./miri toolchain
+        shell: bash
+
+      - name: Show Rust version (miri toolchain)
+        run: |
+          rustup show
+          rustc -Vv
+          cargo -V
+        shell: bash