diff --git a/pkgs/development/java-modules/build-maven-package.nix b/pkgs/development/java-modules/build-maven-package.nix
index b3c3e1732e0..499b2c65b77 100644
--- a/pkgs/development/java-modules/build-maven-package.nix
+++ b/pkgs/development/java-modules/build-maven-package.nix
@@ -13,8 +13,8 @@ in stdenv.mkDerivation rec {
 
   propagatedBuildInput = [ maven ] ++ flatDeps;
 
-  find = ''find ${foldl' (x: y: x + " " + y) "" (map (x: x + "/m2") flatDeps)} -type d -printf '%P\n' | xargs -I {} mkdir -p $out/m2/{}'';
-  copy = ''cp -rsfu ${foldl' (x: y: x + " " + y) "" (map (x: x + "/m2/*") flatDeps)} $out/m2'';
+  find = ''find ${concatStringsSep " " (map (x: x + "/m2") flatDeps)} -type d -printf '%P\n' | xargs -I {} mkdir -p $out/m2/{}'';
+  copy = ''cp -rsfu ${concatStringsSep " " (map (x: x + "/m2/*") flatDeps)} $out/m2'';
 
   phases = [ "unpackPhase" "buildPhase" ];