diff --git a/navi/auth/_ddl.py b/navi/auth/_ddl.py
index 35a1a29..8850e38 100644
--- a/navi/auth/_ddl.py
+++ b/navi/auth/_ddl.py
@@ -34,13 +34,38 @@
 CREATE INDEX IF NOT EXISTS idx_user_auth_sessions_user_id ON user_auth_sessions (user_id);
 """
 
+# Columns added after initial table creation — boot-time migration.
+_NAVI_USERS_MIGRATION_COLUMNS = [
+    ("username", "TEXT"),
+    ("first_name", "TEXT"),
+    ("last_name", "TEXT"),
+    ("phone", "TEXT"),
+    ("birth_date", "TEXT"),
+    ("country", "TEXT"),
+    ("city", "TEXT"),
+    ("locale", "TEXT"),
+]
+
 
 async def _ensure_auth_tables() -> None:
-    """Create auth tables if they don't exist."""
+    """Create auth tables if they don't exist and run boot-time migrations."""
     from navi.config import settings
 
     conn = await asyncpg.connect(settings.database_url)
     try:
         await conn.execute(_DDL)
+        # Migrate existing navi_users tables that lack newer columns
+        for col_name, col_type in _NAVI_USERS_MIGRATION_COLUMNS:
+            row = await conn.fetchrow(
+                """
+                SELECT 1 FROM information_schema.columns
+                WHERE table_name = 'navi_users' AND column_name = $1
+                """,
+                col_name,
+            )
+            if row is None:
+                await conn.execute(
+                    f'ALTER TABLE navi_users ADD COLUMN {col_name} {col_type}'
+                )
     finally:
         await conn.close()