diff --git a/.github/actions/cross-tests/action.yml b/.github/actions/cross-tests/action.yml
deleted file mode 100644
index dc89526..0000000
--- a/.github/actions/cross-tests/action.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: "cross-tests"
-
-inputs:
-  rust:
-    required: true
-  package:
-    required: true
-  target:
-    required: true
-  features:
-    required: true
-
-runs:
-  using: "composite"
-  steps:
-      - uses: actions/checkout@v3
-      - uses: RustCrypto/actions/cargo-cache@master
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ inputs.rust }}
-          targets: ${{ inputs.target }}
-      - uses: RustCrypto/actions/cross-install@master
-      - if: ${{ inputs.features != 'NO_FEATURE' }}
-        run: |
-          cd ${{ inputs.package }}
-          cross test --target ${{ inputs.target }} --no-default-features \
-            --features ${{ inputs.features }}
-        shell: bash
-      - if: ${{ inputs.features == 'NO_FEATURE' }}
-        run: |
-          cd ${{ inputs.package }}
-          cross test --target ${{ inputs.target }} --no-default-features
-        shell: bash
diff --git a/.github/workflows/ascon.yml b/.github/workflows/ascon.yml
index d840f90..9950ff9 100644
--- a/.github/workflows/ascon.yml
+++ b/.github/workflows/ascon.yml
@@ -65,3 +65,28 @@ jobs:
       - run: cargo test --no-default-features
       - run: cargo test
       - run: cargo test --all-features
+
+  miri:
+    runs-on: ubuntu-latest
+    env:
+      MIRIFLAGS: "-Zmiri-symbolic-alignment-check -Zmiri-strict-provenance"
+    strategy:
+      matrix:
+        target:
+          - x86_64-unknown-linux-gnu
+          - s390x-unknown-linux-gnu
+    steps:
+      - uses: actions/checkout@v4
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: nightly
+      - name: Install Miri
+        run: |
+          rustup component add miri
+          cargo miri setup
+      - name: Test with Miri
+        run: |
+          cargo miri test --target ${{ matrix.target }} --no-default-features
+          cargo miri test --target ${{ matrix.target }}
+          cargo miri test --target ${{ matrix.target }} --all-features
diff --git a/.github/workflows/keccak.yml b/.github/workflows/keccak.yml
index 9f9dc7f..80081db 100644
--- a/.github/workflows/keccak.yml
+++ b/.github/workflows/keccak.yml
@@ -80,36 +80,30 @@ jobs:
       - run: cargo check --features simd
       - run: cargo test --features simd
 
-  # Cross-compiled tests
-  cross:
-    needs: set-msrv
+  miri:
+    runs-on: ubuntu-latest
+    env:
+      MIRIFLAGS: "-Zmiri-symbolic-alignment-check -Zmiri-strict-provenance"
     strategy:
       matrix:
-        rust:
-          - ${{needs.set-msrv.outputs.msrv}}
-          - stable
         target:
-          - i686-unknown-linux-gnu
           - x86_64-unknown-linux-gnu
-          - aarch64-unknown-linux-gnu
-          - powerpc-unknown-linux-gnu
-        features:
-          - no_unroll
-          - 'NO_FEATURE'
-
-    runs-on: ubuntu-latest
-    defaults:
-      run:
-      # Cross mounts only current package, i.e. by default it ignores workspace's Cargo.toml
-        working-directory: .
+          - s390x-unknown-linux-gnu
     steps:
       - uses: actions/checkout@v4
-      - uses: ./.github/actions/cross-tests
+      - uses: dtolnay/rust-toolchain@master
         with:
-          rust: ${{ matrix.rust }}
-          package: ${{ github.workflow }}
-          target: ${{ matrix.target }}
-          features: ${{ matrix.features }}
+          toolchain: nightly
+      - name: Install Miri
+        run: |
+          rustup component add miri
+          cargo miri setup
+      - name: Test with Miri
+        run: |
+          cargo miri test --target ${{ matrix.target }} --no-default-features
+          cargo miri test --target ${{ matrix.target }}
+          cargo miri test --target ${{ matrix.target }} --features no_unroll
+          cargo miri test --target ${{ matrix.target }} --features simd
 
   aarch64-sha3:
     needs: set-msrv