diff --git a/targets/RT/USER/lte-ru.c b/targets/RT/USER/lte-ru.c
index 93a2440b94..1f8d6aac81 100644
--- a/targets/RT/USER/lte-ru.c
+++ b/targets/RT/USER/lte-ru.c
@@ -678,6 +678,7 @@ static void *emulatedRF_thread(void *param) {
   req.tv_sec = 0;
   req.tv_nsec = (numerology>0)? ((microsec * 1000L)/numerology):(microsec * 1000L)*2;
   cpu_set_t cpuset;
+  CPU_ZERO(&cpuset);
   CPU_SET(1,&cpuset);
   pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
   int policy;