diff --git a/pkgs/by-name/po/postfix-tlspol/package.nix b/pkgs/by-name/po/postfix-tlspol/package.nix
index 8afc3bf69676..f3d2c5a2f0f2 100644
--- a/pkgs/by-name/po/postfix-tlspol/package.nix
+++ b/pkgs/by-name/po/postfix-tlspol/package.nix
@@ -27,5 +27,6 @@ buildGoModule rec {
     homepage = "https://github.com/Zuplu/postfix-tlspol";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ valodim ];
+    mainProgram = "postfix-tlspol";
   };
 }