diff --git a/bumble/device.py b/bumble/device.py
index c5547dd..3725fbb 100644
--- a/bumble/device.py
+++ b/bumble/device.py
@@ -383,8 +383,12 @@ class LegacyAdvertiser:
         # Set the advertising parameters
         await self.device.send_command(
             hci.HCI_LE_Set_Advertising_Parameters_Command(
-                advertising_interval_min=self.device.advertising_interval_min,
-                advertising_interval_max=self.device.advertising_interval_max,
+                advertising_interval_min=int(
+                    self.device.advertising_interval_min / 0.625
+                ),
+                advertising_interval_max=int(
+                    self.device.advertising_interval_max / 0.625
+                ),
                 advertising_type=int(self.advertising_type),
                 own_address_type=self.own_address_type,
                 peer_address_type=self.peer_address.address_type,