diff --git a/prestart.sh b/prestart.sh
index 5635993..1f0f672 100644
--- a/prestart.sh
+++ b/prestart.sh
@@ -55,7 +55,9 @@ async def set_passwords():
         async with engine.begin() as conn:
             for role in roles:
                 try:
-                    await conn.execute(text(f'ALTER ROLE {role} WITH LOGIN PASSWORD :pwd'), {'pwd': pwd})
+                    # ALTER ROLE doesn't support prepared statement parameters
+                    # so we inline the password (extracted from DB URL, safe)
+                    await conn.execute(text(f"ALTER ROLE {role} WITH LOGIN PASSWORD '{pwd}'"))
                     print(f'[prestart] Password set for {role}')
                 except Exception as e:
                     print(f'[prestart] WARNING: Could not set password for {role}: {e}')