diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index 311f60795bae..670b9087f110 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -112,7 +112,8 @@ let
       echo "OK"
 
       filesToFixup="$(for i in "$out"/*; do
-        grep -l '\B\(/usr\)\?/s\?bin' "$i" || :
+        # list all files referring to (/usr)/bin paths, but allow references to /bin/sh.
+        grep -P -l '\B(?!\/bin\/sh\b)(\/usr)?\/bin(?:\/.*)?' "$i" || :
       done)"
 
       if [ -n "$filesToFixup" ]; then
diff --git a/pkgs/tools/filesystems/bcache-tools/default.nix b/pkgs/tools/filesystems/bcache-tools/default.nix
index f6dfdd84d8c4..58f6a05992e9 100644
--- a/pkgs/tools/filesystems/bcache-tools/default.nix
+++ b/pkgs/tools/filesystems/bcache-tools/default.nix
@@ -35,10 +35,6 @@ stdenv.mkDerivation rec {
     "UDEVLIBDIR=${placeholder "out"}/lib/udev/"
   ];
 
-  preBuild = ''
-    sed -e "s|/bin/sh|${bash}/bin/sh|" -i *.rules
-  '';
-
   preInstall = ''
     mkdir -p "$out/sbin" "$out/lib/udev/rules.d" "$out/share/man/man8"
   '';