diff --git a/flake.lock b/flake.lock
index 586c08e0..4dc1b240 100644
--- a/flake.lock
+++ b/flake.lock
@@ -18,17 +18,17 @@
     },
     "newNixpkgs": {
       "locked": {
-        "lastModified": 1647023429,
-        "narHash": "sha256-LdMTXEgW+G1LXrGrME1b1CpTC6/r+meFZDHeXR2Ps40=",
+        "lastModified": 1647380550,
+        "narHash": "sha256-909TI9poX7CIUiFx203WL29YON6m/I6k0ExbZvR7bLM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9b095223a5dc9a6bce6ec54477f31194871eca8e",
+        "rev": "6e3ee8957637a60f5072e33d78e05c0f65c54366",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "nixos-unstable-small",
         "repo": "nixpkgs",
-        "rev": "9b095223a5dc9a6bce6ec54477f31194871eca8e",
         "type": "github"
       }
     },
diff --git a/flake.nix b/flake.nix
index a0c4ff74..e9cc4d2b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,8 +3,7 @@
 
   # FIXME: All the pinned versions of nix/nixpkgs have a broken foreman (yes,
   # even 2.7.0's Nixpkgs pin).
-  # FIXME: has updated prometheus-cpp: https://github.com/NixOS/nixpkgs/pull/163695
-  inputs.newNixpkgs.url = "github:NixOS/nixpkgs/9b095223a5dc9a6bce6ec54477f31194871eca8e";
+  inputs.newNixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
   inputs.nixpkgs.follows = "nix/nixpkgs";
   inputs.nix.url = github:NixOS/nix/2.6.0;