diff --git a/lib.nix b/lib.nix
index b83cbc7..77fa854 100644
--- a/lib.nix
+++ b/lib.nix
@@ -145,8 +145,8 @@ in
           set -euo pipefail
           mkdir -p ${lib.escapeShellArg runtimeDir}
 
-          PGDATA=$(realpath ${data_dir})
-          PGHOST=$(realpath ${runtimeDir})
+          PGDATA=${data_dir}
+          PGHOST=${runtimeDir}
           PGPORT=${builtins.toString port}
           echo "Starting postgres with PGDATA=''${PGDATA} PGHOST=''${PGHOST} PGPORT=''${PGPORT}"
           export PGDATA PGHOST PGPORT