diff --git a/pkgs/build-support/nuke-references/darwin-sign-fixup.sh b/pkgs/build-support/nuke-references/darwin-sign-fixup.sh
deleted file mode 100644
index 940c18e5a627..000000000000
--- a/pkgs/build-support/nuke-references/darwin-sign-fixup.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-# Fixup hook for nukeReferences, not stdenv
-
-source @signingUtils@
-
-fixupHooks+=(signIfRequired)
diff --git a/pkgs/build-support/nuke-references/default.nix b/pkgs/build-support/nuke-references/default.nix
index 6bdb81477aac..13f2061b5aa8 100644
--- a/pkgs/build-support/nuke-references/default.nix
+++ b/pkgs/build-support/nuke-references/default.nix
@@ -11,12 +11,6 @@
   shell ? stdenvNoCC.shell,
 }:
 
-let
-  stdenv = stdenvNoCC;
-
-  darwinCodeSign = stdenv.targetPlatform.isDarwin && stdenv.targetPlatform.isAarch64;
-in
-
 stdenvNoCC.mkDerivation {
   name = "nuke-references";
 
@@ -32,17 +26,14 @@ stdenvNoCC.mkDerivation {
     chmod a+x $out/bin/nuke-refs
   '';
 
-  postFixup = lib.optionalString darwinCodeSign ''
-    mkdir -p $out/nix-support
-    substituteAll ${./darwin-sign-fixup.sh} $out/nix-support/setup-hooks.sh
-  '';
-
   # FIXME: get rid of perl dependency.
   env = {
     inherit perl;
     inherit (builtins) storeDir;
     shell = lib.getBin shell + (shell.shellPath or "");
-    signingUtils = lib.optionalString darwinCodeSign signingUtils;
+    signingUtils = lib.optionalString (
+      stdenvNoCC.targetPlatform.isDarwin && stdenvNoCC.targetPlatform.isAarch64
+    ) signingUtils;
   };
 
   meta.mainProgram = "nuke-refs";
diff --git a/pkgs/build-support/nuke-references/nuke-refs.sh b/pkgs/build-support/nuke-references/nuke-refs.sh
index 21eb855cbad9..8a5a65973fca 100644
--- a/pkgs/build-support/nuke-references/nuke-refs.sh
+++ b/pkgs/build-support/nuke-references/nuke-refs.sh
@@ -2,8 +2,8 @@
 
 fixupHooks=()
 
-if [ -e @out@/nix-support/setup-hooks.sh ]; then
-    source @out@/nix-support/setup-hooks.sh
+if [[ -n "@signingUtils@" ]]; then
+    source "@signingUtils@"
 fi
 
 excludes=""
@@ -25,9 +25,8 @@ for i in "$@"; do
         cat "$i" | @perl@/bin/perl -pe "s|\Q@storeDir@\E/$excludes[a-z0-9]{32}-|@storeDir@/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-|g" > "$i.tmp"
         if test -x "$i"; then chmod +x "$i.tmp"; fi
         mv "$i.tmp" "$i"
-
-        for hook in "${fixupHooks[@]}"; do
-            eval "$hook" "$i"
-        done
+        if [[ -n "@signingUtils@" ]]; then
+            signIfRequired "$i"
+        fi
     fi
 done
diff --git a/pkgs/build-support/remove-references-to/darwin-sign-fixup.sh b/pkgs/build-support/remove-references-to/darwin-sign-fixup.sh
deleted file mode 100644
index 940c18e5a627..000000000000
--- a/pkgs/build-support/remove-references-to/darwin-sign-fixup.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-# Fixup hook for nukeReferences, not stdenv
-
-source @signingUtils@
-
-fixupHooks+=(signIfRequired)
diff --git a/pkgs/build-support/remove-references-to/default.nix b/pkgs/build-support/remove-references-to/default.nix
index 6ae3e3125c85..13d3eb8a78d8 100644
--- a/pkgs/build-support/remove-references-to/default.nix
+++ b/pkgs/build-support/remove-references-to/default.nix
@@ -10,13 +10,7 @@
   shell ? stdenvNoCC.shell,
 }:
 
-let
-  stdenv = stdenvNoCC;
-
-  darwinCodeSign = stdenv.targetPlatform.isDarwin && stdenv.targetPlatform.isAarch64;
-in
-
-stdenv.mkDerivation {
+stdenvNoCC.mkDerivation {
   name = "remove-references-to";
 
   dontUnpack = true;
@@ -29,16 +23,13 @@ stdenv.mkDerivation {
     chmod a+x $out/bin/remove-references-to
   '';
 
-  postFixup = lib.optionalString darwinCodeSign ''
-    mkdir -p $out/nix-support
-    substituteAll ${./darwin-sign-fixup.sh} $out/nix-support/setup-hooks.sh
-  '';
-
   env = {
     inherit (builtins) storeDir;
     shell = lib.getBin shell + (shell.shellPath or "");
-  }
-  // lib.optionalAttrs darwinCodeSign { inherit signingUtils; };
+    signingUtils = lib.optionalString (
+      stdenvNoCC.targetPlatform.isDarwin && stdenvNoCC.targetPlatform.isAarch64
+    ) signingUtils;
+  };
 
   meta.mainProgram = "remove-references-to";
 }
diff --git a/pkgs/build-support/remove-references-to/remove-references-to.sh b/pkgs/build-support/remove-references-to/remove-references-to.sh
index a4d068eb591e..e24524d0c574 100755
--- a/pkgs/build-support/remove-references-to/remove-references-to.sh
+++ b/pkgs/build-support/remove-references-to/remove-references-to.sh
@@ -2,10 +2,6 @@
 
 fixupHooks=()
 
-if [ -e @out@/nix-support/setup-hooks.sh ]; then
-    source @out@/nix-support/setup-hooks.sh
-fi
-
 # References to remove
 targets=()
 while getopts t: o; do
@@ -30,8 +26,9 @@ for target in "${targets[@]}" ; do
     sed -i -e "s|$target|eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee|g" "${regions[@]}"
 done
 
-for region in "${regions[@]}"; do
-    for hook in "${fixupHooks[@]}"; do
-        eval "$hook" "$region"
+if [[ -n "@signingUtils@" ]]; then
+    source "@signingUtils@"
+    for region in "${regions[@]}"; do
+        signIfRequired "$region"
     done
-done
+fi