diff --git a/devShells/default.nix b/devShells/default.nix
index 964758a..3b1618f 100644
--- a/devShells/default.nix
+++ b/devShells/default.nix
@@ -57,13 +57,9 @@ in
       pkgs.gcc
       pkgs.gnumake
     ];
-    emacs-lisp = extendDevShell nix [
-      ## TODO: This works on aarch64-darwin in unstable and master, but not
-      ##       25.05. I haven’t needed it, so it’s easier to disable until 25.11
-      ##       than to work around.
-      # pkgs.cask
-      pkgs.emacs
-      pkgs.emacsPackages.eldev
+    dhall = extendDevShell nix [
+      pkgs.dhall
+      pkgs.dhall-docs
     ];
     haskell = extendDevShell nix ([
         pkgs.cabal-install
@@ -88,24 +84,29 @@ in
         ++ [
           pkgs.cargo
           pkgs.cargo-fuzz
-          pkgs.cargo-semver-checks
+          (pkgs.cargo-semver-checks.overrideAttrs (old: {
+            ## NB: Checks fail on aarch64 systems with Nixpkgs 25.11.
+            doCheck = !pkgs.stdenv.isAarch64;
+          }))
           pkgs.rust-analyzer
           pkgs.rustPackages.clippy
           pkgs.rustc
           pkgs.rustfmt
           (pkgs.rustup.overrideAttrs (old: {
-            ## NB: Fails on i686-linux with Nixpkgs 24.11.
-            doCheck = pkgs.system != "i686-linux";
+            ## NB: Checks fail on aarch64-darwin with Nixpkgs 25.11.
+            doCheck = pkgs.system != "aarch64-darwin";
           }))
         ]);
   }
   // (
     if pkgs.system != sys.i686-linux
     then {
-      ## `cborg-0.2.9.0` fails to build on i686-linux
-      dhall = extendDevShell nix [
-        pkgs.dhall
-        pkgs.dhall-docs
+      ## guile is broken on i686-linux in Nixpkgs 25.11
+      emacs-lisp = extendDevShell nix [
+        ## TODO: Doesn’t build on Nixpkgs 25.11
+        # pkgs.cask
+        pkgs.emacs
+        pkgs.emacsPackages.eldev
       ];
       ## `openjdk-19.0.2+7` isn’t supported on i686-linux
       scala = extendDevShell nix [pkgs.sbt];
diff --git a/flake.lock b/flake.lock
index 1f8c340..d966bda 100644
--- a/flake.lock
+++ b/flake.lock
@@ -26,11 +26,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1764551295,
-        "narHash": "sha256-jC68TKt+z3t8auC6Z/H/W/n/ZCfoS5mksRyLbxD5Zr8=",
+        "lastModified": 1766982994,
+        "narHash": "sha256-OGhwUC3F6RUjBuAZa7mtMuDavdWQOH0zch7SHGD8V4g=",
         "owner": "sellout",
         "repo": "bash-strict-mode",
-        "rev": "37eaa2e33d24168e0a903ddd9828666c1b91f867",
+        "rev": "15c08bfdeb2a353d27c8703ef49d27dde9953602",
         "type": "github"
       },
       "original": {
@@ -87,11 +87,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1765170151,
-        "narHash": "sha256-+xEEmpoSWckv5iXx7xmM6TFnrf6hMwbNoeGb8k2ln0M=",
+        "lastModified": 1767588577,
+        "narHash": "sha256-4AP5l787tHrrcfZgGz/fWlOiGZkS7QGi1zr8JZ+zmAo=",
         "owner": "sellout",
         "repo": "flaky",
-        "rev": "71bb45755c9fa8be812a9a5d47f7489ea61db5c3",
+        "rev": "0e29685f5512b72b7991f3f02d5a1e07482cafec",
         "type": "github"
       },
       "original": {
@@ -123,32 +123,32 @@
         ]
       },
       "locked": {
-        "lastModified": 1763992789,
-        "narHash": "sha256-WHkdBlw6oyxXIra/vQPYLtqY+3G8dUVZM8bEXk0t8x4=",
+        "lastModified": 1767514898,
+        "narHash": "sha256-ONYqnKrPzfKEEPChoJ9qPcfvBqW9ZgieDKD7UezWPg4=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "44831a7eaba4360fb81f2acc5ea6de5fde90aaa3",
+        "rev": "7a06e8a2f844e128d3b210a000a62716b6040b7f",
         "type": "github"
       },
       "original": {
         "owner": "nix-community",
-        "ref": "release-25.05",
+        "ref": "release-25.11",
         "repo": "home-manager",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1765136434,
-        "narHash": "sha256-3IZiSEpm+8sd4MxWS2cpAO3jyP+vY61G+C1Fyk7lJss=",
+        "lastModified": 1767563445,
+        "narHash": "sha256-GIyPDpWOR7a3k3yY9cPz5ymyFGxZmOG4e/FseY6e33A=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "875a6ee9e533ca31f03cb5d0ee809f006204a4d9",
+        "rev": "044f759a4f4629f2be41e59b859753a091e3c089",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "release-25.05",
+        "ref": "release-25.11",
         "repo": "nixpkgs",
         "type": "github"
       }
diff --git a/templates/haskell/.config/flake/outputs.nix b/templates/haskell/.config/flake/outputs.nix
index ec2785a..2720bcb 100644
--- a/templates/haskell/.config/flake/outputs.nix
+++ b/templates/haskell/.config/flake/outputs.nix
@@ -96,7 +96,7 @@ in
         "ghc" + nixpkgs.lib.replaceStrings ["."] [""] version;
 
       ## TODO: Extract this automatically from `pkgs.haskellPackages`.
-      defaultGhcVersion = "9.8.4";
+      defaultGhcVersion = "9.10.3";
 
       ## Test the oldest revision possible for each minor release. If it’s not
       ## available in nixpkgs, test the oldest available, then try an older
@@ -105,14 +105,11 @@ in
       ## maps to in the nixpkgs we depend on.
       testedGhcVersions = system: [
         self.lib.defaultGhcVersion
-        "8.10.7"
-        "9.0.2"
-        "9.2.8"
-        "9.4.7"
-        "9.6.3"
-        "9.8.1"
-        "9.10.1"
-        "9.12.1"
+        "9.4.8"
+        "9.6.7"
+        "9.8.4"
+        "9.10.2"
+        "9.12.2"
         # "ghcHEAD" # doctest doesn’t work on current HEAD
       ];
 
@@ -138,16 +135,7 @@ in
 
       ## However, provide packages in the default overlay for _every_
       ## supported version.
-      supportedGhcVersions = system:
-        self.lib.testedGhcVersions system
-        ++ [
-          "9.4.8"
-          "9.6.4"
-          "9.6.5"
-          "9.8.2"
-          "9.10.2"
-          "9.12.2"
-        ];
+      supportedGhcVersions = self.lib.testedGhcVersions;
     };
   }
   // flake-utils.lib.eachSystem supportedSystems
diff --git a/templates/haskell/core/{{project.name}}.cabal b/templates/haskell/core/{{project.name}}.cabal
index c9ec217..41e0901 100644
--- a/templates/haskell/core/{{project.name}}.cabal
+++ b/templates/haskell/core/{{project.name}}.cabal
@@ -29,14 +29,14 @@ tested-with:
     8.4.1,
     8.6.1,
     8.8.1,
-    8.10.1, 8.10.7,
-    9.0.1, 9.0.2,
-    9.2.1, 9.2.8,
-    9.4.1, 9.4.7,
-    9.6.1, 9.6.3,
+    8.10.1,
+    9.0.1,
+    9.2.1,
+    9.4.1, 9.4.8,
+    9.6.1, 9.6.7,
     9.8.1, 9.8.4,
-    9.10.1,
-    9.12.1
+    9.10.1, 9.10.2, 9.10.3,
+    9.12.1, 9.12.2
   }
 
 homepage: https://github.com/{{project.repo}}#readme