diff --git a/pkgs/os-specific/darwin/apple-source-releases/copyfile/package.nix b/pkgs/os-specific/darwin/apple-source-releases/copyfile/package.nix
index b2c02c05e624..413e6532b3a6 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/copyfile/package.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/copyfile/package.nix
@@ -71,15 +71,6 @@ mkAppleDerivation {
 
   xcodeHash = "sha256-SYW6pBlCQkcbkBqCq+W/mDYZZ7/co2HlPZwXzgh/LnI=";
 
-  postPatch = ''
-    # Disable experimental bounds safety stuff that’s not available in LLVM 16.
-    for header in copyfile.h xattr_flags.h; do
-      substituteInPlace "$header" \
-        --replace-fail '__ptrcheck_abi_assume_single()' "" \
-        --replace-fail '__unsafe_indexable' ""
-    done
-  '';
-
   env.NIX_CFLAGS_COMPILE = "-I${privateHeaders}/include";
 
   meta.description = "Darwin file copying library";