diff --git a/nix/default.nix b/nix/default.nix
index b244f5e858d1a3a85d3f99732853704b193779d3..4f4457dc178be4e48519e751cf2e6aa526a2a384 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -21,7 +21,7 @@ let
     # haskell.nix provides access to the nixpkgs pins which are used by our CI,
     # hence you will be more likely to get cache hits when using these.
     # But you can also just use your own, e.g. '<nixpkgs>'.
-    haskellNix.sources.nixpkgs-2105
+    haskellNix.sources.nixpkgs-2111
     # These arguments passed to nixpkgs, include some patches and also
     # the haskell.nix functionality itself as an overlay.
     (haskellNix.nixpkgsArgs // { overlays = allOverlays; });
diff --git a/nix/sources.json b/nix/sources.json
index fc5bbbbb6468aed32a38328e7577a4fd2a54c2a9..a6a9c21c29e2a869d2a6b820fde41ee535314819 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -5,10 +5,10 @@
         "homepage": "https://input-output-hk.github.io/haskell.nix",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "f624ca56629d5be438c7d44a721b0c1d944eda23",
-        "sha256": "0529blc9ck19vnk235ap9g0vi8afmaw9i22a4v6w1gq37mz2p6hb",
+        "rev": "e95a1f0dacbc64603c31d11e36e4ba1af8f0eb43",
+        "sha256": "160cf7ha2c5wkbymy3h4skzw1l3x4i8dhj2arvq3bdz92gg1d6cb",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/f624ca56629d5be438c7d44a721b0c1d944eda23.tar.gz",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/e95a1f0dacbc64603c31d11e36e4ba1af8f0eb43.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "niv": {
@@ -24,15 +24,15 @@
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs": {
-        "branch": "release-21.05",
+        "branch": "nixos-21.11",
         "description": "Nix Packages collection",
         "homepage": "",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "92609f3d9bc3acffbdbe54fa1c591a885612aa73",
-        "sha256": "09n9j2lr8632xrslpwsk4222xcq7h1f7lj0vjc2b90v3c64hqwml",
+        "rev": "573095944e7c1d58d30fc679c81af63668b54056",
+        "sha256": "07s5cwhskqvy82b4rld9b14ljc0013pig23i3jx3l3f957rk95pg",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/92609f3d9bc3acffbdbe54fa1c591a885612aa73.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/573095944e7c1d58d30fc679c81af63668b54056.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }