diff --git a/postgresql.json b/postgresql.json
index 0cadcea920..5a1a0e995b 100644
--- a/postgresql.json
+++ b/postgresql.json
@@ -25,7 +25,7 @@
         "PGDATA": "$dir\\data"
     },
     "post_install": "
-        if (!(Test-Path \"$dir\\data\\pg_hba.conf\")) { iex \"initdb --encoding=UTF8 --locale=en\" }
+        if (!(Test-Path \"$dir\\data\\pg_hba.conf\")) { iex \"initdb --username=postgres --encoding=UTF8 --locale=en\" }
     ",
     "notes": "To start/stop service, run `pg_ctl start`, `pg_ctl stop`.",
     "checkver": {