diff --git a/flake.lock b/flake.lock
index 05831e7..93dea2d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1682018913,
-        "narHash": "sha256-Eo2ZkWB8+qy8fnmxtJUNJl6HHYYAgXDR29+OwDIzm1Q=",
+        "lastModified": 1682929865,
+        "narHash": "sha256-jxVrgnf5QNjO+XoxDxUWtN2G5xyJSGZ5SWDQFxMuHxc=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "7048a48bc79b4361f77740420000d2b5454b0df7",
+        "rev": "f2e9a130461950270f87630b11132323706b4d91",
         "type": "github"
       },
       "original": {
@@ -51,11 +51,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1682043560,
-        "narHash": "sha256-ZsF4Yee9pQbvLtwSVGgYux+az4yFSLXrxPyGHm3ptJM=",
+        "lastModified": 1682907601,
+        "narHash": "sha256-FfUAYvRJ+6s9WWjXNPdRzuuvAeu2VHIXIbUkPJr4t14=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "48037a6f8faeee138ede96bf607bc95c9dab9aec",
+        "rev": "5eaff055dd57128c53ae373dc96af944f5849daa",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index e13db21..f54e6cc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -98,7 +98,7 @@ rec {
           devShells.default = pkgs.mkShell {
             nativeBuildInputs = with pkgs; [
               # Override the stable rustfmt.
-              rustPkgs.rust-nightly_2023-01-01.availableComponents.rustfmt
+              rustPkgs.rust-nightly_2023-05-01.availableComponents.rustfmt
               # Follows nixpkgs's version of rustc.
               (let vers = lib.splitVersion rustc.version; in
                 rustPkgs."rust_${lib.elemAt vers 0}_${lib.elemAt vers 1}_${lib.elemAt vers 2}")