diff --git a/nixos/pkgs/megacli2prom/default.nix b/nixos/pkgs/megacli2prom/default.nix
index e5021d7583777f73ff6ff725c77f724ef4dc697a..60c77e8b7e230de5c92374d0144e205b8a71c855 100644
--- a/nixos/pkgs/megacli2prom/default.nix
+++ b/nixos/pkgs/megacli2prom/default.nix
@@ -11,7 +11,7 @@ pkgs.stdenv.mkDerivation {
   src = repo;
   prePatch = ''
     substituteInPlace ./megacli2prom.py \
-      --replace '/opt/MegaRAID/MegaCli/MegaCli64' '${pkgs.megacli}/opt/MegaRAID/MegaCli/MegaCli64'
+      --replace '/opt/MegaRAID/MegaCli/MegaCli64' '${pkgs.megacli}/bin/MegaCli64'
   '';
   installPhase = ''
     mkdir -p $out/bin