diff --git a/flake.nix b/flake.nix
index 33297a34..3fa8acbf 100644
--- a/flake.nix
+++ b/flake.nix
@@ -42,7 +42,12 @@
           kairosNodeAttrs = {
             src = lib.cleanSourceWith {
               src = craneLib.path ./.;
-              filter = path: type: craneLib.filterCargoSources path type;
+              filter = path: type:
+                # Allow static files.
+                (lib.hasInfix "/fixtures/" path) ||
+                # Default filter (from crane) for .rs files.
+                (craneLib.filterCargoSources path type)
+              ;
             };
             nativeBuildInputs = with pkgs; [ pkg-config ];