diff --git a/pkgs/by-name/op/openmolcas/package.nix b/pkgs/by-name/op/openmolcas/package.nix
index 3e63afa83d0f..249983e53c4b 100644
--- a/pkgs/by-name/op/openmolcas/package.nix
+++ b/pkgs/by-name/op/openmolcas/package.nix
@@ -48,11 +48,6 @@ let
   nevpt2Src = stdenv.mkDerivation {
     pname = "nevpt2-src";
     version = "unstable";
-    phases = [
-      "unpackPhase"
-      "patchPhase"
-      "installPhase"
-    ];
     src = fetchFromGitHub {
       owner = "qcscine";
       repo = "nevpt2";