diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7641f20..2fdf037 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,8 +23,8 @@ concurrency:
 
 jobs:
 
-  test_310:
-    name: "Python 3.10 Tests"
+  test_311:
+    name: "Python 3.11 Tests"
 
     runs-on: ubuntu-22.04
 
diff --git a/pyproject.toml b/pyproject.toml
index 8e7f076..79ff269 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,7 +46,6 @@ flake8-debugger = "*"
 flake8-deprecated = "*"
 flake8-docstrings = "*"
 flake8-ensure-ascii = "*"
-flake8-mutable = "*"
 flake8-plone-hasattr = "*"
 flake8-print = "*"
 flake8-self = "*"
diff --git a/shell.nix b/shell.nix
index 2b22d10..5d40e64 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,13 +1,13 @@
 let
   nixpkgs = builtins.fetchTarball {
-    # https://github.com/NixOS/nixpkgs/tree/nixos-22.11 on 2022-11-29
-    url = "https://github.com/nixos/nixpkgs/archive/ce5fe99df1f15a09a91a86be9738d68fadfbad82.tar.gz";
-    sha256 = "1zqyq7v1gxrg2b7zizf4npask4vqbs4s7khwffxafgm20gxngb6a";
+    # https://github.com/NixOS/nixpkgs/tree/nixos-22.11 on 2023-03-23
+    url = "https://github.com/nixos/nixpkgs/archive/9ef6e7727f4c31507627815d4f8679c5841efb00.tar.gz";
+    sha256 = "0w2r5cfrpqmjmjy8azllrbgr5d92if87i9ybgvpk6din4w79ibal";
   };
   poetry2nixsrc = builtins.fetchTarball {
-    # https://github.com/nix-community/poetry2nix/commits/master on 2022-11-29
-    url = "https://github.com/nix-community/poetry2nix/archive/ce8425ccc2884c1065927a38d1700024f431cf0f.tar.gz";
-    sha256 = "07x48abw18qfxdmsz8hdd762vj8n5l2syh9xm40v851bhidbjswc";
+    # https://github.com/nix-community/poetry2nix/commits/master on 2023-03-23
+    url = "https://github.com/nix-community/poetry2nix/archive/50ec694c27a12bc178fff961c4dd927fa6a47f18.tar.gz";
+    sha256 = "1s596k78sbzjmh5l7rzaf27f97r87dia1zyxkadir5s8vvjvw4ya";
   };
 
   # Fix for installing PasteDeploy from https://github.com/nix-community/poetry2nix/issues/750
@@ -30,7 +30,7 @@ let
   };
 
   devEnv = poetry2nix.mkPoetryEnv ({
-    python = pkgs.python310;
+    python = pkgs.python311;
     projectDir = ./.;
     editablePackageSources = {
       pyramid_openapi3 = ./.;