diff --git a/.github/workflows/ci-cheri.yml b/.github/workflows/ci-cheri.yml
index da46b4174..479694e01 100644
--- a/.github/workflows/ci-cheri.yml
+++ b/.github/workflows/ci-cheri.yml
@@ -30,7 +30,7 @@ jobs:
 
     - name: System dependencies (ubuntu)
       run: |
-        sudo apt install build-essential libgmp-dev opam
+        sudo apt-get install build-essential libgmp-dev opam
 
     - name: Restore cached opam
       id: cache-opam-restore
@@ -38,25 +38,7 @@ jobs:
       with:
         path: ~/.opam
         key: ${{ matrix.version }}
-
-    - name: Setup opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      run: |
-        eval $(opam env --switch=with_coq)
-        opam repo add --yes --this-switch coq-released https://coq.inria.fr/opam/released
-        opam pin --yes -n coq-struct-tact https://github.com/uwplse/StructTact.git
-        opam repo add --yes --this-switch iris-dev https://gitlab.mpi-sws.org/iris/opam.git
-        opam pin --yes -n coq-sail-stdpp https://github.com/rems-project/coq-sail.git#f319aad
-        opam pin --yes -n coq-cheri-capabilities https://github.com/rems-project/coq-cheri-capabilities.git
-        opam install --deps-only --yes ./cerberus-lib.opam ./cerberus-cheri.opam
-
-    - name: Save cached opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      id: cache-opam-save
-      uses: actions/cache/save@v4
-      with:
-        path: ~/.opam
-        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+        fail-on-cache-miss: true
 
     - name: Install Cerberus-CHERI
       if: ${{ matrix.version == '4.14.1' }}
diff --git a/.github/workflows/ci-cn-bench.yml b/.github/workflows/ci-cn-bench.yml
index 4acda0fcd..d7111a663 100644
--- a/.github/workflows/ci-cn-bench.yml
+++ b/.github/workflows/ci-cn-bench.yml
@@ -35,7 +35,7 @@ jobs:
 
     - name: System dependencies (ubuntu)
       run: |
-        sudo apt install build-essential libgmp-dev z3 opam jq
+        sudo apt-get install build-essential libgmp-dev z3 opam jq
 
     - name: Restore cached opam
       id: cache-opam-restore
@@ -43,21 +43,7 @@ jobs:
       with:
         path: ~/.opam
         key: ${{ matrix.version }}
-
-    - name: Setup opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      run: |
-        opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
-        opam install --deps-only --yes ./cerberus-lib.opam
-        opam switch create with_coq ${{ matrix.version }}
-
-    - name: Save cached opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      id: cache-opam-save
-      uses: actions/cache/save@v4
-      with:
-        path: ~/.opam
-        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+        fail-on-cache-miss: true
 
     - name: Install Cerberus
       run: |
diff --git a/.github/workflows/ci-cn-spec-testing.yml b/.github/workflows/ci-cn-spec-testing.yml
index 0be117ca0..69166b5ef 100644
--- a/.github/workflows/ci-cn-spec-testing.yml
+++ b/.github/workflows/ci-cn-spec-testing.yml
@@ -31,7 +31,7 @@ jobs:
 
     - name: System dependencies (ubuntu)
       run: |
-        sudo apt install build-essential libgmp-dev z3 opam cmake
+        sudo apt-get install build-essential libgmp-dev z3 opam cmake
 
     - name: Restore cached opam
       id: cache-opam-restore
@@ -39,20 +39,7 @@ jobs:
       with:
         path: ~/.opam
         key: ${{ matrix.version }}
-
-    - name: Setup opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      run: |
-        opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
-        opam install --deps-only --yes ./cerberus-lib.opam
-
-    - name: Save cached opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      id: cache-opam-save
-      uses: actions/cache/save@v4
-      with:
-        path: ~/.opam
-        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+        fail-on-cache-miss: true
 
     - name: Install Cerberus
       run: |
diff --git a/.github/workflows/ci-cn.yml b/.github/workflows/ci-cn.yml
index 98ced7836..7889d279c 100644
--- a/.github/workflows/ci-cn.yml
+++ b/.github/workflows/ci-cn.yml
@@ -29,7 +29,7 @@ jobs:
 
     - name: System dependencies (ubuntu)
       run: |
-        sudo apt install build-essential libgmp-dev z3 opam
+        sudo apt-get install build-essential libgmp-dev z3 opam
 
     - name: Restore cached opam
       id: cache-opam-restore
@@ -37,20 +37,7 @@ jobs:
       with:
         path: ~/.opam
         key: ${{ matrix.version }}
-
-    - name: Setup opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      run: |
-        opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
-        opam install --deps-only --yes ./cerberus-lib.opam
-
-    - name: Save cached opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      id: cache-opam-save
-      uses: actions/cache/save@v4
-      with:
-        path: ~/.opam
-        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+        fail-on-cache-miss: true
 
     - name: Install Cerberus
       run: |
diff --git a/.github/workflows/ci-pr-bench.yml.disabled b/.github/workflows/ci-pr-bench.yml.disabled
index 921c7d774..534460f5d 100644
--- a/.github/workflows/ci-pr-bench.yml.disabled
+++ b/.github/workflows/ci-pr-bench.yml.disabled
@@ -45,28 +45,7 @@ jobs:
       with:
         path: ~/.opam
         key: ${{ matrix.version }}
-
-    - name: Setup opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      run: |
-        opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
-        opam install --deps-only --yes ./cerberus-lib.opam
-        opam switch create with_coq ${{ matrix.version }}
-        eval $(opam env --switch=with_coq)
-        opam repo add --yes --this-switch coq-released https://coq.inria.fr/opam/released
-        opam pin --yes -n coq-struct-tact https://github.com/uwplse/StructTact.git
-        opam repo add --yes --this-switch iris-dev https://gitlab.mpi-sws.org/iris/opam.git
-        opam pin --yes -n coq-sail-stdpp https://github.com/rems-project/coq-sail.git#f319aad
-        opam pin --yes -n coq-cheri-capabilities https://github.com/rems-project/coq-cheri-capabilities.git
-        opam install --deps-only --yes ./cerberus-lib.opam ./cerberus-cheri.opam
-
-    - name: Save cached opam
-      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
-      id: cache-opam-save
-      uses: actions/cache/save@v4
-      with:
-        path: ~/.opam
-        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+        fail-on-cache-miss: true
 
     - name: Install python dependencies
       run: pip install tabulate
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 481e5a1ee..93d535f5b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,7 +30,7 @@ jobs:
 
     - name: System dependencies (ubuntu)
       run: |
-        sudo apt install build-essential libgmp-dev z3 opam cmake
+        sudo apt-get install build-essential libgmp-dev z3 opam cmake
 
     - name: Restore cached opam
       id: cache-opam-restore
@@ -44,6 +44,14 @@ jobs:
       run: |
         opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
         opam install --deps-only --yes ./cerberus-lib.opam
+        opam switch create with_coq ${{ matrix.version }}
+        eval $(opam env --switch=with_coq)
+        opam repo add --yes --this-switch coq-released https://coq.inria.fr/opam/released
+        opam pin --yes -n coq-struct-tact https://github.com/uwplse/StructTact.git
+        opam repo add --yes --this-switch iris-dev https://gitlab.mpi-sws.org/iris/opam.git
+        opam pin --yes -n coq-sail-stdpp https://github.com/rems-project/coq-sail.git#f319aad
+        opam pin --yes -n coq-cheri-capabilities https://github.com/rems-project/coq-cheri-capabilities.git
+        opam install --deps-only --yes ./cerberus-lib.opam ./cerberus-cheri.opam
 
     - name: Save cached opam
       if: steps.cache-opam-restore.outputs.cache-hit != 'true'