diff --git a/pkgs/build-support/trivial-builders/default.nix b/pkgs/build-support/trivial-builders/default.nix
index 4be06b5c4913..3cc902958ce3 100644
--- a/pkgs/build-support/trivial-builders/default.nix
+++ b/pkgs/build-support/trivial-builders/default.nix
@@ -778,9 +778,6 @@ rec {
         ''
       );
 
-  # Remove after 25.05 branch-off
-  writeReferencesToFile = throw "writeReferencesToFile has been removed. Use writeClosure instead.";
-
   # Docs in doc/build-helpers/trivial-build-helpers.chapter.md
   # See https://nixos.org/manual/nixpkgs/unstable/#trivial-builder-writeClosure
   writeClosure =
diff --git a/pkgs/by-name/fl/flattenReferencesGraph/src/flatten_references_graph/popularity_contest.py b/pkgs/by-name/fl/flattenReferencesGraph/src/flatten_references_graph/popularity_contest.py
index 7ab7b3acb6b0..c8447d655479 100644
--- a/pkgs/by-name/fl/flattenReferencesGraph/src/flatten_references_graph/popularity_contest.py
+++ b/pkgs/by-name/fl/flattenReferencesGraph/src/flatten_references_graph/popularity_contest.py
@@ -3,8 +3,7 @@
 # and how deep in the tree they live. Equally-"popular" paths are then
 # sorted by name.
 #
-# The existing writeReferencesToFile prints the paths in a simple
-# ascii-based sorting of the paths.
+# The existing writeClosure prints the paths in a simple ascii-based sorting of the paths.
 #
 # Sorting the paths by graph improves the chances that the difference
 # between two builds appear near the end of the list, instead of near