diff --git a/mail_gateway/models/mail_message.py b/mail_gateway/models/mail_message.py
index df3e23ff5a..91695e0ec5 100644
--- a/mail_gateway/models/mail_message.py
+++ b/mail_gateway/models/mail_message.py
@@ -27,7 +27,9 @@ class MailMessage(models.Model):
         string="Child gateway messages",
     )
     gateway_message_id = fields.Many2one(
-        "mail.message", string="Original gateway message"
+        "mail.message",
+        string="Original gateway message",
+        index=True,
     )
     gateway_thread_data = fields.Json(compute="_compute_gateway_thread_data")
 
diff --git a/mail_gateway_whatsapp/models/mail_thread.py b/mail_gateway_whatsapp/models/mail_thread.py
index aac28a4c61..2f60bfa38f 100644
--- a/mail_gateway_whatsapp/models/mail_thread.py
+++ b/mail_gateway_whatsapp/models/mail_thread.py
@@ -31,7 +31,6 @@ def _whatsapp_get_channel(self, field_name, gateway):
         partner = self._whatsapp_get_partner()
         if not self.env["res.partner.gateway.channel"].search(
             [
-                ("partner_id", "=", partner.id),
                 ("gateway_id", "=", gateway.id),
                 ("gateway_token", "=", sanitized_number),
             ]