diff --git a/flake.nix b/flake.nix
index 7c4bcea5a..5fd4d585f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,6 +1,6 @@
 {
   description = "A modern SAT solver in Rust";
-  inputs.nixpkgs.url = github:NixOS/nixpkgs;
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs";
   outputs = { self, nixpkgs }:
   {
     packages = builtins.listToAttrs