diff --git a/connectivity/lorawan/mbed_lib.json b/connectivity/lorawan/mbed_lib.json
index 3b8bcbb58e1..576f4092afd 100644
--- a/connectivity/lorawan/mbed_lib.json
+++ b/connectivity/lorawan/mbed_lib.json
@@ -102,7 +102,8 @@
     "target_overrides": {
         "STM32WL": {
             "wakeup-time": 3,
-            "max-sys-rx-error": 10
+            "max-sys-rx-error": 10,
+            "downlink-preamble-length": 8
         }
     }
 }