diff --git a/pkgs/build-support/trivial-builders.nix b/pkgs/build-support/trivial-builders.nix
index 1815c99a9f4..c8f0272daf8 100644
--- a/pkgs/build-support/trivial-builders.nix
+++ b/pkgs/build-support/trivial-builders.nix
@@ -112,7 +112,7 @@ _EOF_
   # the default binary.
   useSetUID = drv: path:
     let
-      name = stdenv.lib.basename path;
+      name = baseNameOf path;
       bin = "${drv}${path}";
     in assert name != "";
       writeScript "setUID-${name}" ''
diff --git a/pkgs/lib/strings.nix b/pkgs/lib/strings.nix
index 8f918acf7b2..5f2670913e2 100644
--- a/pkgs/lib/strings.nix
+++ b/pkgs/lib/strings.nix
@@ -153,10 +153,6 @@ rec {
         s;
 
         
-  # Why do we need this if we have baseNameOf?
-  basename = s: lib.last (splitString "/" s);
-
-
   # Return true iff string v1 denotes a version older than v2.
   versionOlder = v1: v2: builtins.compareVersions v2 v1 == 1;