diff --git a/lib.nix b/lib.nix
index 82778dd..8a27826 100644
--- a/lib.nix
+++ b/lib.nix
@@ -142,7 +142,7 @@ in
         name = "run-postgres";
         text = ''
           set -euo pipefail
-          export PGDATA=$(realpath ${data_dir}) PGHOST=$(realpath (${runtimeDir}) PGPORT=${builtins.toString port}
+          export PGDATA=$(realpath ${data_dir}) PGHOST=$(realpath ${runtimeDir}) PGPORT=${builtins.toString port}
           mkdir -p ${lib.escapeShellArg runtimeDir}
           ${setupScript}/bin/setup-postgres
           ${package}/bin/postgres