diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
new file mode 100644
index 0000000..79460d5
--- /dev/null
+++ b/.github/workflows/nix.yml
@@ -0,0 +1,15 @@
+name: "Nix"
+on:
+  pull_request:
+  push:
+jobs:
+  nix:
+    name: Nix on ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2.4.0
+    - uses: cachix/install-nix-action@v15
+    - run: nix build --show-trace
diff --git a/Cargo.lock b/Cargo.lock
index a9578c1..474d8b3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -278,7 +278,7 @@ dependencies = [
 [[package]]
 name = "fatfs"
 version = "0.4.0"
-source = "git+https://github.com/rafalh/rust-fatfs#87fc1ed5074a32b4e0344fcdde77359ef9e75432"
+source = "git+https://github.com/rafalh/rust-fatfs?rev=87fc1ed5074a32b4e0344fcdde77359ef9e75432#87fc1ed5074a32b4e0344fcdde77359ef9e75432"
 dependencies = [
  "bitflags",
  "chrono",
diff --git a/examples/fat/src/fat/Cargo.toml b/examples/fat/src/fat/Cargo.toml
index 56c464e..b08e075 100644
--- a/examples/fat/src/fat/Cargo.toml
+++ b/examples/fat/src/fat/Cargo.toml
@@ -10,7 +10,7 @@ path = "lib.rs"
 crate-type = ["cdylib"]
 
 [dependencies]
-fatfs = { git = "https://github.com/rafalh/rust-fatfs" }
+fatfs = { git = "https://github.com/rafalh/rust-fatfs", rev = "87fc1ed5074a32b4e0344fcdde77359ef9e75432" }
 fscommon = "0.1"
 ic-cdk = { git = "https://github.com/dfinity/cdk-rs.git", rev = "a253119adb08929b6304d007ee0a6a37960656ed" }
 ic-cdk-macros = "0.3"
diff --git a/flake.lock b/flake.lock
index 525a1f7..a06779d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -31,37 +31,22 @@
         "type": "github"
       }
     },
-    "mozillapkgs": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1638887313,
-        "narHash": "sha256-FMYV6rVtvSIfthgC1sK1xugh3y7muoQcvduMdriz4ag=",
-        "owner": "mozilla",
-        "repo": "nixpkgs-mozilla",
-        "rev": "7c1e8b1dd6ed0043fb4ee0b12b815256b0b9de6f",
-        "type": "github"
-      },
-      "original": {
-        "owner": "mozilla",
-        "repo": "nixpkgs-mozilla",
-        "type": "github"
-      }
-    },
     "naersk": {
       "inputs": {
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1639947939,
-        "narHash": "sha256-pGsM8haJadVP80GFq4xhnSpNitYNQpaXk4cnA796Cso=",
-        "owner": "nix-community",
+        "lastModified": 1641890987,
+        "narHash": "sha256-CJOAOlk7mZlBVvUiv9q8SYkK0rjY0UmkWedMI0eajWE=",
+        "owner": "mhuesch",
         "repo": "naersk",
-        "rev": "2fc8ce9d3c025d59fee349c1f80be9785049d653",
+        "rev": "193e049d6e4c841faf800e302551d2e0a48eee88",
         "type": "github"
       },
       "original": {
-        "owner": "nix-community",
+        "owner": "mhuesch",
         "repo": "naersk",
+        "rev": "193e049d6e4c841faf800e302551d2e0a48eee88",
         "type": "github"
       }
     },
@@ -79,6 +64,21 @@
         "type": "indirect"
       }
     },
+    "nixpkgs-mozilla": {
+      "locked": {
+        "lastModified": 1645464064,
+        "narHash": "sha256-YeN4bpPvHkVOpQzb8APTAfE7/R+MFMwJUMkqmfvytSk=",
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "rev": "15b7a05f20aab51c4ffbefddb1b448e862dccb7d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "type": "github"
+      }
+    },
     "nixpkgs_2": {
       "locked": {
         "lastModified": 1638239011,
@@ -99,9 +99,9 @@
       "inputs": {
         "dfinity-sdk": "dfinity-sdk",
         "flake-utils": "flake-utils",
-        "mozillapkgs": "mozillapkgs",
         "naersk": "naersk",
-        "nixpkgs": "nixpkgs_2"
+        "nixpkgs": "nixpkgs_2",
+        "nixpkgs-mozilla": "nixpkgs-mozilla"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index 10f27ef..60f3341 100644
--- a/flake.nix
+++ b/flake.nix
@@ -5,12 +5,13 @@
       flake = false;
     };
     flake-utils.url = "github:numtide/flake-utils";
-    mozillapkgs = {
-      url = "github:mozilla/nixpkgs-mozilla";
-      flake = false;
-    };
-    naersk.url = "github:nix-community/naersk";
+
+    # https://github.com/nix-community/naersk/pull/211
+    naersk.url = "github:mhuesch/naersk?rev=193e049d6e4c841faf800e302551d2e0a48eee88";
+    # naersk.url = "github:nix-community/naersk";
+
     nixpkgs.url = "github:nixos/nixpkgs/21.11";
+    nixpkgs-mozilla.url = "github:mozilla/nixpkgs-mozilla";
   };
 
   outputs = {
@@ -18,8 +19,8 @@
     nixpkgs,
     dfinity-sdk,
     flake-utils,
-    mozillapkgs,
     naersk,
+    nixpkgs-mozilla,
   }:
     flake-utils.lib.eachDefaultSystem (
       system: let
@@ -31,11 +32,10 @@
         };
 
         # Get a specific rust version
-        mozilla = pkgs.callPackage (mozillapkgs + "/package-set.nix") {};
+        mozilla = pkgs.callPackage (nixpkgs-mozilla + "/package-set.nix") {};
         rust = (mozilla.rustChannelOf {
-          channel = "stable";
-          version = "1.54.0";
-          sha256 = "NL+YHnOj1++1O7CAaQLijwAxKJW9SnHg8qsiOJ1m0Kk=";
+          channel = "1.55.0";
+          sha256 = "HNIlEerJvk6sBfd8zugzwSgSiHcQH8ZbqWQn9BGfmpo=";
           # sha256 = pkgs.lib.fakeSha256;
         }).rust.override {
           extensions = [