diff --git a/.github/workflows/nix-action-8.16.yml b/.github/workflows/nix-action-8.16.yml
index 204377d0..ec94cbe3 100644
--- a/.github/workflows/nix-action-8.16.yml
+++ b/.github/workflows/nix-action-8.16.yml
@@ -3481,6 +3481,7 @@ jobs:
     needs:
     - coq
     - mathcomp-reals
+    - mathcomp-bigenough
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -3531,6 +3532,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-reals'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16" --argstr
         job "mathcomp-reals"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-bigenough'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16" --argstr
+        job "mathcomp-bigenough"
     - 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 "8.16" --argstr
diff --git a/.github/workflows/nix-action-8.17.yml b/.github/workflows/nix-action-8.17.yml
index 5f58afe9..ca193b36 100644
--- a/.github/workflows/nix-action-8.17.yml
+++ b/.github/workflows/nix-action-8.17.yml
@@ -3404,6 +3404,7 @@ jobs:
     needs:
     - coq
     - mathcomp-reals
+    - mathcomp-bigenough
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -3454,6 +3455,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-reals'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.17" --argstr
         job "mathcomp-reals"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-bigenough'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.17" --argstr
+        job "mathcomp-bigenough"
     - 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 "8.17" --argstr
diff --git a/.github/workflows/nix-action-8.18.yml b/.github/workflows/nix-action-8.18.yml
index b8045565..70634e95 100644
--- a/.github/workflows/nix-action-8.18.yml
+++ b/.github/workflows/nix-action-8.18.yml
@@ -3342,6 +3342,7 @@ jobs:
     needs:
     - coq
     - mathcomp-reals
+    - mathcomp-bigenough
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -3392,6 +3393,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-reals'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.18" --argstr
         job "mathcomp-reals"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-bigenough'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.18" --argstr
+        job "mathcomp-bigenough"
     - 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 "8.18" --argstr
diff --git a/.github/workflows/nix-action-8.19.yml b/.github/workflows/nix-action-8.19.yml
index 95d5adf4..aac109ed 100644
--- a/.github/workflows/nix-action-8.19.yml
+++ b/.github/workflows/nix-action-8.19.yml
@@ -3255,6 +3255,7 @@ jobs:
     needs:
     - coq
     - mathcomp-reals
+    - mathcomp-bigenough
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -3305,6 +3306,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-reals'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.19" --argstr
         job "mathcomp-reals"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-bigenough'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.19" --argstr
+        job "mathcomp-bigenough"
     - 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 "8.19" --argstr
diff --git a/.github/workflows/nix-action-8.20.yml b/.github/workflows/nix-action-8.20.yml
index 7b110f9e..5dc778cf 100644
--- a/.github/workflows/nix-action-8.20.yml
+++ b/.github/workflows/nix-action-8.20.yml
@@ -2546,6 +2546,7 @@ jobs:
     needs:
     - coq
     - mathcomp-reals
+    - mathcomp-bigenough
     - hierarchy-builder
     runs-on: ubuntu-latest
     steps:
@@ -2596,6 +2597,10 @@ jobs:
       name: 'Building/fetching previous CI target: mathcomp-reals'
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.20" --argstr
         job "mathcomp-reals"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: mathcomp-bigenough'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.20" --argstr
+        job "mathcomp-bigenough"
     - 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 "8.20" --argstr
diff --git a/.nix/nixpkgs.nix b/.nix/nixpkgs.nix
index 4dad36aa..ff2c6469 100644
--- a/.nix/nixpkgs.nix
+++ b/.nix/nixpkgs.nix
@@ -1,4 +1,4 @@
 fetchTarball {
-    url = https://github.com/NixOS/nixpkgs/archive/355e12b665339290efd7d08180d423973d70228f.tar.gz;
-    sha256 = "0rw76fniaz2ihw2nhn2fhn2b6mcl2y6r49dv4hjb9n4w9q9csak5";
+    url = https://github.com/NixOS/nixpkgs/archive/9850a3dbb17e57f499acc1f65cf5705597e590f4.tar.gz;
+    sha256 = "0aajvgr5m0fnmchjcg5bh1yvm9jm3spslp9r8aab36vp3mk5gp1c";
   }