diff --git a/srsepc/src/mme/s1ap.cc b/srsepc/src/mme/s1ap.cc
index 4b1bbd688..0dce45c41 100644
--- a/srsepc/src/mme/s1ap.cc
+++ b/srsepc/src/mme/s1ap.cc
@@ -542,8 +542,9 @@ s1ap::activate_eps_bearer(uint64_t imsi, uint8_t ebi)
 uint32_t
 s1ap::allocate_m_tmsi(uint64_t imsi)
 {
-  uint32_t m_tmsi = m_next_m_tmsi++;
-  //uint32_t m_tmsi = m_next_m_tmsi;
+  uint32_t m_tmsi = m_next_m_tmsi;
+  m_next_m_tmsi = (m_next_m_tmsi + 1) % UINT32_MAX;
+
   m_tmsi_to_imsi.insert(std::pair<uint32_t,uint64_t>(m_tmsi,imsi));
   m_s1ap_log->debug("Allocated M-TMSI 0x%x to IMSI %015lu,\n",m_tmsi,imsi);
   return m_tmsi;
diff --git a/srsepc/src/mme/s1ap_nas_transport.cc b/srsepc/src/mme/s1ap_nas_transport.cc
index eb64a09eb..f64e4ff0d 100644
--- a/srsepc/src/mme/s1ap_nas_transport.cc
+++ b/srsepc/src/mme/s1ap_nas_transport.cc
@@ -25,6 +25,7 @@
  */
 
 #include <iostream>
+#include <cmath>
 #include "mme/s1ap.h"
 #include "mme/s1ap_nas_transport.h"
 #include "srslte/common/security.h"