diff --git a/lib/include/srslte/asn1/liblte_mme.h b/lib/include/srslte/asn1/liblte_mme.h
index 780793683..485a5f077 100644
--- a/lib/include/srslte/asn1/liblte_mme.h
+++ b/lib/include/srslte/asn1/liblte_mme.h
@@ -2525,6 +2525,10 @@ const char* liblte_nas_sec_hdr_type_to_string(int code);
 #define LIBLTE_MME_MSG_TYPE_CS_SERVICE_NOTIFICATION                                       0x64
 #define LIBLTE_MME_MSG_TYPE_DOWNLINK_GENERIC_NAS_TRANSPORT                                0x68
 #define LIBLTE_MME_MSG_TYPE_UPLINK_GENERIC_NAS_TRANSPORT                                  0x69
+#define LIBLTE_MME_MSG_TYPE_ACTIVATE_TEST_MODE                                            0x84
+#define LIBLTE_MME_MSG_TYPE_ACTIVATE_TEST_MODE_COMPLETE                                   0x85
+#define LIBLTE_MME_MSG_TYPE_DEACTIVATE TEST MODE                                          0x86
+#define LIBLTE_MME_MSG_TYPE_DEACTIVATE_TEST_MODE_COMPLETE                                 0x87
 #define LIBLTE_MME_MSG_TYPE_ACTIVATE_DEFAULT_EPS_BEARER_CONTEXT_REQUEST                   0xC1
 #define LIBLTE_MME_MSG_TYPE_ACTIVATE_DEFAULT_EPS_BEARER_CONTEXT_ACCEPT                    0xC2
 #define LIBLTE_MME_MSG_TYPE_ACTIVATE_DEFAULT_EPS_BEARER_CONTEXT_REJECT                    0xC3
@@ -2548,6 +2552,9 @@ const char* liblte_nas_sec_hdr_type_to_string(int code);
 #define LIBLTE_MME_MSG_TYPE_ESM_INFORMATION_RESPONSE                                      0xDA
 #define LIBLTE_MME_MSG_TYPE_NOTIFICATION                                                  0xDB
 #define LIBLTE_MME_MSG_TYPE_ESM_STATUS                                                    0xE8
+#define LIBLTE_MME_MSG_TYPE_TEST_MODE_PROTOCOL_DISCRIMINATOR                              0xF
+#define LIBLTE_MME_MSG_TYPE_TEST_MODE_SKIP_INDICATOR                                      0x0
+
 const char* liblte_nas_msg_type_to_string(int code);
 
 // Enums
@@ -3427,6 +3434,8 @@ typedef struct{
 }LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT;
 // Functions
 LIBLTE_ERROR_ENUM liblte_mme_pack_activate_dedicated_eps_bearer_context_accept_msg(LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT *act_ded_eps_bearer_context_accept,
+                                                                                   uint8                                                              sec_hdr_type,
+                                                                                   uint32                                                             count,
                                                                                    LIBLTE_BYTE_MSG_STRUCT                                             *msg);
 LIBLTE_ERROR_ENUM liblte_mme_unpack_activate_dedicated_eps_bearer_context_accept_msg(LIBLTE_BYTE_MSG_STRUCT                                             *msg,
                                                                                      LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT *act_ded_eps_bearer_context_accept);
@@ -4050,4 +4059,21 @@ LIBLTE_ERROR_ENUM liblte_mme_pack_pdn_disconnect_request_msg(LIBLTE_MME_PDN_DISC
 LIBLTE_ERROR_ENUM liblte_mme_unpack_pdn_disconnect_request_msg(LIBLTE_BYTE_MSG_STRUCT                       *msg,
                                                                LIBLTE_MME_PDN_DISCONNECT_REQUEST_MSG_STRUCT *pdn_discon_req);
 
+/*********************************************************************
+    Message Name: ACTIVATE TEST MODE COMPLETE
+
+    Description: Sent by the UE to the network in response to an
+                 ATTACH ACCEPT message.
+
+    Document Reference: 36.509 v8.7.0 Section 6.6
+*********************************************************************/
+// Defines
+// Enums
+// Structs
+// Functions
+LIBLTE_ERROR_ENUM liblte_mme_pack_activate_test_mode_complete_msg(LIBLTE_BYTE_MSG_STRUCT *msg,
+                                                                  uint8                   sec_hdr_type,
+                                                                  uint32                  count);
+
+
 #endif // SRSLTE_LIBLTE_MME_H
diff --git a/lib/src/asn1/liblte_mme.cc b/lib/src/asn1/liblte_mme.cc
index aef20de60..4d81cb56b 100644
--- a/lib/src/asn1/liblte_mme.cc
+++ b/lib/src/asn1/liblte_mme.cc
@@ -8547,6 +8547,8 @@ LIBLTE_ERROR_ENUM liblte_mme_unpack_uplink_generic_nas_transport_msg(LIBLTE_BYTE
     Document Reference: 24.301 v10.2.0 Section 8.3.1
 *********************************************************************/
 LIBLTE_ERROR_ENUM liblte_mme_pack_activate_dedicated_eps_bearer_context_accept_msg(LIBLTE_MME_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT_MSG_STRUCT *act_ded_eps_bearer_context_accept,
+                                                                                   uint8                                                              sec_hdr_type,
+                                                                                   uint32                                                             count,
                                                                                    LIBLTE_BYTE_MSG_STRUCT                                             *msg)
 {
     LIBLTE_ERROR_ENUM  err     = LIBLTE_ERROR_INVALID_INPUTS;
@@ -8555,6 +8557,20 @@ LIBLTE_ERROR_ENUM liblte_mme_pack_activate_dedicated_eps_bearer_context_accept_m
     if(act_ded_eps_bearer_context_accept != NULL &&
        msg                               != NULL)
     {
+        if(LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS != sec_hdr_type)
+        {
+          // Protocol Discriminator and Security Header Type
+          *msg_ptr = (sec_hdr_type << 4) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
+          msg_ptr++;
+
+          // MAC will be filled in later
+          msg_ptr += 4;
+
+          // Sequence Number
+          *msg_ptr = count & 0xFF;
+          msg_ptr++;
+        }
+
         // Protocol Discriminator and EPS Bearer ID
         *msg_ptr = (act_ded_eps_bearer_context_accept->eps_bearer_id << 4) | (LIBLTE_MME_PD_EPS_SESSION_MANAGEMENT);
         msg_ptr++;
@@ -11207,6 +11223,47 @@ LIBLTE_ERROR_ENUM liblte_mme_unpack_pdn_disconnect_request_msg(LIBLTE_BYTE_MSG_S
     return(err);
 }
 
+
+LIBLTE_ERROR_ENUM liblte_mme_pack_activate_test_mode_complete_msg(LIBLTE_BYTE_MSG_STRUCT *msg,
+                                                                  uint8                   sec_hdr_type,
+                                                                  uint32                  count)
+{
+    LIBLTE_ERROR_ENUM  err     = LIBLTE_ERROR_INVALID_INPUTS;
+    uint8             *msg_ptr = msg->msg;
+
+    if(msg         != NULL)
+    {
+        if(LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS != sec_hdr_type)
+        {
+            // Protocol Discriminator and Security Header Type
+            *msg_ptr = (sec_hdr_type << 4) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
+            msg_ptr++;
+
+            // MAC will be filled in later
+            msg_ptr += 4;
+
+            // Sequence Number
+            *msg_ptr = count & 0xFF;
+            msg_ptr++;
+        }
+
+        // Protocol Discriminator and skip indicator (always 0x0F)
+        *msg_ptr = (LIBLTE_MME_MSG_TYPE_TEST_MODE_SKIP_INDICATOR << 4) | (LIBLTE_MME_MSG_TYPE_TEST_MODE_PROTOCOL_DISCRIMINATOR);
+        msg_ptr++;
+
+        // Message Type
+        *msg_ptr = LIBLTE_MME_MSG_TYPE_ACTIVATE_TEST_MODE_COMPLETE;
+        msg_ptr++;
+
+        // Fill in the number of bytes used
+        msg->N_bytes = msg_ptr - msg->msg;
+
+        err = LIBLTE_SUCCESS;
+    }
+
+    return(err);
+}
+
 /*******************************************************************************
                               HELPER FUNCTIONS
 *******************************************************************************/