diff --git a/nix/plugin.nix b/nix/plugin.nix
index 7c7eb0e..9483077 100644
--- a/nix/plugin.nix
+++ b/nix/plugin.nix
@@ -37,14 +37,14 @@ let
   # Args shared between the deps-only build (cached on Cargo.lock changes only)
   # and the final crate build. cxx-qt-build runs during the deps build too, so it
   # needs the Qt env to find qmltyperegistrar/qmlcachegen.
-  # Default cleanCargoSource only keeps .rs/.toml/.lock; we also need
-  # qt_plugin_exports.txt (linker --dynamic-list file referenced by build.rs).
+  # Default cleanCargoSource only keeps .rs/.toml/.lock; also keep the linker
+  # --dynamic-list file referenced by build.rs.
   pluginSrc = lib.cleanSourceWith {
     src = ../plugin;
     name = "nova-plugin-source";
     filter =
       path: type:
-      (builtins.match ".*\\.txt$" path != null) || (craneLib.filterCargoSources path type);
+      (baseNameOf path == "qt_plugin_exports.txt") || (craneLib.filterCargoSources path type);
   };
 
   commonArgs = {