diff --git a/flake.nix b/flake.nix
index 252427f..182baea 100644
--- a/flake.nix
+++ b/flake.nix
@@ -45,8 +45,8 @@
 
           src = sourceByRegex self [
             "(src|tests)(/.*)?"
-            "Cargo\\.(toml|lock)"
-            "build.rs"
+            ''Cargo\.(toml|lock)''
+            ''build\.rs''
           ];
         in
         rustPlatform.buildRustPackage {