diff --git a/pkgs/development/compilers/ghc/abi-depends-determinism.nix b/pkgs/development/compilers/ghc/abi-depends-determinism.nix
index afa272d03a8..bc803b74617 100644
--- a/pkgs/development/compilers/ghc/abi-depends-determinism.nix
+++ b/pkgs/development/compilers/ghc/abi-depends-determinism.nix
@@ -2,8 +2,10 @@
 # cached abi-depends fields in package databases, modified to only
 # contain hunks that exist in distribution tarballs.
 { fetchpatch, runCommand }: let
-  base = fetchpatch { # Non-determinism in cached abi-depends fields
-    url = https://phabricator-files.haskell.org/file/data/4pqrbo5b62sifktfbrls/PHID-FILE-4g4zjiqlfxmmlaos7lz7/D4159.diff;
+  base = fetchpatch rec { # Non-determinism in cached abi-depends fields
+    # Originally https://phabricator-files.haskell.org/file/data/4pqrbo5b62sifktfbrls/PHID-FILE-4g4zjiqlfxmmlaos7lz7/D4159.diff
+    url = "http://tarballs.nixos.org/sha256/${sha256}";
+    name = "D4159.diff";
     sha256 = "0b8a08sisf1swmarm6nh9rgw7cpzi2rwdzvrd6ny49c7wk0f7x4b";
   };
 in runCommand base.name {}