diff --git a/.github/workflows/nix-action.yml b/.github/workflows/nix-action.yml
index bdfb96e093..7a1c9cb00b 100644
--- a/.github/workflows/nix-action.yml
+++ b/.github/workflows/nix-action.yml
@@ -86,6 +86,42 @@ jobs:
     - name: Building/fetching current CI target
       run: nix-build --no-out-link --argstr task "${{ matrix.task }}" --argstr job "mathcomp-analysis"
 
+  "multinomials":
+    runs-on: ubuntu-latest
+    needs:
+      - setup
+      - "_deps"
+    strategy:
+      matrix:
+        task:
+          - "coq-8.13"
+          - "coq-8.12"
+          - "coq-8.11+multinomials"
+    steps:
+    - name: Cachix install
+      uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: coq
+    - name: Cachix setup math-comp
+      uses: cachix/cachix-action@v8
+      with:
+        # Name of a cachix cache to pull/substitute
+        name: math-comp
+        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+    - name: Git checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Building/fetching previous target _deps
+      run: nix-build --no-out-link --argstr task "${{ matrix.task }}" --argstr job "_deps"
+    - name: Building/fetching current CI target
+      run: nix-build --no-out-link --argstr task "${{ matrix.task }}" --argstr job "multinomials"
+
   "_allJobs":
     runs-on: ubuntu-latest
     needs:
diff --git a/.nix/fallback-config.nix b/.nix/fallback-config.nix
index eaca48dc90..e3fb69ddde 100644
--- a/.nix/fallback-config.nix
+++ b/.nix/fallback-config.nix
@@ -44,6 +44,7 @@
   tasks."coq-8.13" = {
       coqPackages."coq".override.version = "8.13";
       coqPackages."mathcomp".override.version = "1.12.0";
+      coqPackages."mathcomp".job = "_excluded";
       coqPackages."mathcomp-real-closed".override.version = "1.1";
       coqPackages."mathcomp-finmap".override.version = "1.5";
       coqPackages."hierarchy-builder".override.version = "1.0.0";
diff --git a/meta.yml b/meta.yml
index 5651221123..910fd8f8ac 100644
--- a/meta.yml
+++ b/meta.yml
@@ -10,19 +10,25 @@ coqdoc: false
 nix: true
 nix-default:
   ref: simpler-ci-jobs
+
 cachix:
 - name: coq
 - name: math-comp
   token: CACHIX_AUTH_TOKEN
+
 nix-jobs:
 - job: _deps
 - job: mathcomp-analysis
   needs:
     - _deps
+- job: multinomials
+  needs:
+    - _deps
 - job: _allJobs
   needs:
     - _deps
     - mathcomp-analysis
+
 nix-default-task: coq-8.13
 nix-tasks:
 - task: coq-8.13
@@ -31,6 +37,7 @@ nix-tasks:
       version: 8.13
     - name: mathcomp
       version: 1.12.0
+      job: _excluded
     - name: mathcomp-real-closed
       version: 1.1
     - name: mathcomp-finmap