diff --git a/src/hal/hal.h b/src/hal/hal.h
index f831c1ec..ca07f19e 100644
--- a/src/hal/hal.h
+++ b/src/hal/hal.h
@@ -13,6 +13,7 @@
 #define _hal_hal_h_
 
 #include "arduino_lmic_hal_configuration.h"
+#include "lmic/oslmic_types.h"
 
 // for compatbility reasons, we need to disclose the configuration
 // structure as global type lmic_pinmap.