diff --git a/pkgs/tools/networking/isync/default.nix b/pkgs/tools/networking/isync/default.nix
index e26526dc68d..8e21ccee108 100644
--- a/pkgs/tools/networking/isync/default.nix
+++ b/pkgs/tools/networking/isync/default.nix
@@ -29,5 +29,6 @@ stdenv.mkDerivation rec {
     license = licenses.gpl2Plus;
     platforms = platforms.unix;
     maintainers = with maintainers; [ primeos lheckemann ];
+    mainProgram = "mbsync";
   };
 }