diff --git a/.github/workflows/nix-action-coq-8.18.yml b/.github/workflows/nix-action-coq-8.18.yml
index 2fbc8f05c..1a528864d 100644
--- a/.github/workflows/nix-action-coq-8.18.yml
+++ b/.github/workflows/nix-action-coq-8.18.yml
@@ -1,6 +1,7 @@
 jobs:
   Verdi:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -65,6 +66,7 @@ jobs:
         --argstr job "Verdi"
   addition-chains:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-algebra
     - mathcomp-fingroup
@@ -135,6 +137,7 @@ jobs:
         --argstr job "addition-chains"
   autosubst:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -189,10 +192,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
         --argstr job "autosubst"
-  coq-elpi:
+  coq:
     needs: []
     runs-on: ubuntu-latest
     steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{\
+        \ github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha\
+        \ }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{\
+        \ github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{\
+        \ github.event.repository.html_url }} refs/pull/${{ github.event.number }}/merge\
+        \ | cut -f1)\n  mergeable=$(git merge --no-commit --no-ff ${{ github.event.pull_request.base.sha\
+        \ }} > /dev/null 2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n\
+        \  if [ -z \"$merge_commit\" -o \"x$mergeable\" != \"x0\" ]; then\n    echo\
+        \ \"tested_commit=${{ github.event.pull_request.head.sha }}\" >> $GITHUB_ENV\n\
+        \  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v20
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-elpi
+      uses: cachix/cachix-action@v12
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, coq-community, math-comp
+        name: coq-elpi
+    - id: stepCheck
+      name: Checking presence of CI target coq
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr\
+        \ bundle \"coq-8.18\" --argstr job \"coq\" \\\n   --dry-run 2>&1 > /dev/null)\n\
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
+        --argstr job "coq"
+  coq-elpi:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
     - name: Determine which commit to initially checkout
       run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{\
         \ github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha\
@@ -242,6 +293,7 @@ jobs:
         --argstr job "coq-elpi"
   coquelicot:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -298,6 +350,7 @@ jobs:
         --argstr job "coquelicot"
   deriving:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -354,6 +407,7 @@ jobs:
         --argstr job "deriving"
   hierarchy-builder:
     needs:
+    - coq
     - coq-elpi
     runs-on: ubuntu-latest
     steps:
@@ -410,6 +464,7 @@ jobs:
         --argstr job "hierarchy-builder"
   mathcomp:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-fingroup
     - mathcomp-algebra
@@ -496,6 +551,7 @@ jobs:
         --argstr job "mathcomp"
   mathcomp-algebra:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-fingroup
     - hierarchy-builder
@@ -562,6 +618,7 @@ jobs:
         --argstr job "mathcomp-algebra"
   mathcomp-analysis:
     needs:
+    - coq
     - mathcomp-classical
     - mathcomp-field
     - mathcomp-bigenough
@@ -633,6 +690,7 @@ jobs:
         --argstr job "mathcomp-analysis"
   mathcomp-bigenough:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -689,6 +747,7 @@ jobs:
         --argstr job "mathcomp-bigenough"
   mathcomp-character:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-fingroup
     - mathcomp-algebra
@@ -770,7 +829,9 @@ jobs:
         --argstr job "mathcomp-character"
   mathcomp-classical:
     needs:
+    - coq
     - mathcomp-algebra
+    - mathcomp-finmap
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -821,6 +882,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-algebra'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
         --argstr job "mathcomp-algebra"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-finmap'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
+        --argstr job "mathcomp-finmap"
     - if: steps.stepCheck.outputs.status == 'built'
       name: 'Building/fetching previous CI target: hierarchy-builder'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
@@ -831,6 +896,7 @@ jobs:
         --argstr job "mathcomp-classical"
   mathcomp-field:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-fingroup
     - mathcomp-algebra
@@ -907,6 +973,7 @@ jobs:
         --argstr job "mathcomp-field"
   mathcomp-fingroup:
     needs:
+    - coq
     - mathcomp-ssreflect
     - hierarchy-builder
     runs-on: ubuntu-latest
@@ -966,8 +1033,66 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
         --argstr job "mathcomp-fingroup"
+  mathcomp-finmap:
+    needs:
+    - coq
+    - mathcomp-ssreflect
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{\
+        \ github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha\
+        \ }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{\
+        \ github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{\
+        \ github.event.repository.html_url }} refs/pull/${{ github.event.number }}/merge\
+        \ | cut -f1)\n  mergeable=$(git merge --no-commit --no-ff ${{ github.event.pull_request.base.sha\
+        \ }} > /dev/null 2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n\
+        \  if [ -z \"$merge_commit\" -o \"x$mergeable\" != \"x0\" ]; then\n    echo\
+        \ \"tested_commit=${{ github.event.pull_request.head.sha }}\" >> $GITHUB_ENV\n\
+        \  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v20
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-elpi
+      uses: cachix/cachix-action@v12
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, coq-community, math-comp
+        name: coq-elpi
+    - id: stepCheck
+      name: Checking presence of CI target mathcomp-finmap
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr\
+        \ bundle \"coq-8.18\" --argstr job \"mathcomp-finmap\" \\\n   --dry-run 2>&1\
+        \ > /dev/null)\necho $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"\
+        built:\" | sed \"s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
+        --argstr job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-ssreflect'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
+        --argstr job "mathcomp-ssreflect"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "coq-8.18"
+        --argstr job "mathcomp-finmap"
   mathcomp-solvable:
     needs:
+    - coq
     - mathcomp-ssreflect
     - mathcomp-fingroup
     - mathcomp-algebra
@@ -1039,6 +1164,7 @@ jobs:
         --argstr job "mathcomp-solvable"
   mathcomp-ssreflect:
     needs:
+    - coq
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -1095,6 +1221,7 @@ jobs:
         --argstr job "mathcomp-ssreflect"
   odd-order:
     needs:
+    - coq
     - mathcomp-character
     - mathcomp-ssreflect
     - mathcomp-fingroup
@@ -1181,6 +1308,7 @@ jobs:
         --argstr job "odd-order"
   reglang:
     needs:
+    - coq
     - mathcomp-ssreflect
     runs-on: ubuntu-latest
     steps:
@@ -1237,6 +1365,7 @@ jobs:
         --argstr job "reglang"
   trakt:
     needs:
+    - coq
     - coq-elpi
     runs-on: ubuntu-latest
     steps:
diff --git a/.nix/config.nix b/.nix/config.nix
index 86a920d7e..b9488e1f0 100644
--- a/.nix/config.nix
+++ b/.nix/config.nix
@@ -18,6 +18,9 @@
       mathcomp-analysis.override.version = "hierarchy-builder";
       mathcomp-analysis.job = true;
 
+      mathcomp-finmap.override.version = "2.0.0";
+      mathcomp-finmap.job = true;
+
       mathcomp-classical.override.version = "hierarchy-builder";
       mathcomp-classical.job = true;