diff --git a/targets/RT/USER/lte-enb.c b/targets/RT/USER/lte-enb.c
index 659905dd0ba34c7e5e63c3fc5f4cdc1bd53c0fdc..97cb82ce714739815a788b2d94102727c1fbe405 100644
--- a/targets/RT/USER/lte-enb.c
+++ b/targets/RT/USER/lte-enb.c
@@ -128,7 +128,7 @@ extern pthread_cond_t sync_cond;
 extern pthread_mutex_t sync_mutex;
 extern int sync_var;
 
-extern transmission_mode;
+extern int transmission_mode;
 
 //pthread_t                       main_eNB_thread;