diff --git a/pkgs/applications/networking/sync/unison/default.nix b/pkgs/applications/networking/sync/unison/default.nix
index 10bc3ca68637..5245030fd7f3 100644
--- a/pkgs/applications/networking/sync/unison/default.nix
+++ b/pkgs/applications/networking/sync/unison/default.nix
@@ -71,5 +71,6 @@ stdenv.mkDerivation (finalAttrs: {
     license = licenses.gpl3Plus;
     maintainers = with maintainers; [ viric ];
     platforms = platforms.unix;
+    mainProgram = "unison";
   };
 })