diff --git a/include/maxscale/dcb.h b/include/maxscale/dcb.h
index fa551ce3a..27cf49228 100644
--- a/include/maxscale/dcb.h
+++ b/include/maxscale/dcb.h
@@ -313,7 +313,7 @@ int dcb_isvalid(DCB *);                     /* Check the DCB is in the linked li
 int dcb_count_by_usage(DCB_USAGE);          /* Return counts of DCBs */
 int dcb_persistent_clean_count(DCB *, int, bool);      /* Clean persistent and return count */
 void dcb_hangup_foreach (struct server* server);
-uint32_t dcb_get_session_id(DCB* dcb);
+uint64_t dcb_get_session_id(DCB* dcb);
 char *dcb_role_name(DCB *);                  /* Return the name of a role */
 int dcb_accept_SSL(DCB* dcb);
 int dcb_connect_SSL(DCB* dcb);
diff --git a/include/maxscale/protocol/mysql.h b/include/maxscale/protocol/mysql.h
index a07262dae..438655eef 100644
--- a/include/maxscale/protocol/mysql.h
+++ b/include/maxscale/protocol/mysql.h
@@ -320,7 +320,7 @@ typedef struct
     uint32_t               server_capabilities;          /*< server capabilities, created or received */
     uint32_t               client_capabilities;          /*< client capabilities, created or received */
     uint32_t               extra_capabilities;           /*< MariaDB 10.2 capabilities */
-    uint32_t               tid;                          /*< MySQL Thread ID, in handshake */
+    uint64_t               thread_id;                    /*< MySQL Thread ID. Send only 32bits in handshake. */
     unsigned int           charset;                      /*< MySQL character set at connect time */
     int                    ignore_replies;               /*< How many replies should be discarded */
     GWBUF*                 stored_query;                 /*< Temporarily stored queries */
diff --git a/include/maxscale/session.h b/include/maxscale/session.h
index 03f5f4963..240d5990e 100644
--- a/include/maxscale/session.h
+++ b/include/maxscale/session.h
@@ -134,7 +134,7 @@ typedef struct session
 {
     skygw_chk_t             ses_chk_top;
     mxs_session_state_t     state;            /*< Current descriptor state */
-    uint32_t                ses_id;           /*< Unique session identifier */
+    uint64_t                ses_id;           /*< Unique session identifier */
     struct dcb              *client_dcb;      /*< The client connection */
     struct mxs_router_session *router_session;  /*< The router instance data */
     MXS_SESSION_STATS       stats;            /*< Session statistics */
@@ -194,7 +194,7 @@ MXS_SESSION *session_alloc(struct service *, struct dcb *);
  * @param id            Id for the new session.
  * @return              The newly created session or NULL if an error occurred
  */
-MXS_SESSION *session_alloc_with_id(struct service *, struct dcb *, uint32_t);
+MXS_SESSION *session_alloc_with_id(struct service *, struct dcb *, uint64_t);
 
 MXS_SESSION *session_set_dummy(struct dcb *);
 
@@ -352,14 +352,14 @@ static inline bool session_set_autocommit(MXS_SESSION* ses, bool autocommit)
  *
  * @note The caller must free the session reference by calling session_put_ref
  */
-MXS_SESSION* session_get_by_id(uint32_t id);
+MXS_SESSION* session_get_by_id(uint64_t id);
 
 /**
  * Get the next available unique (assuming no overflow) session id number.
  *
  * @return An unused session id.
  */
-uint32_t session_get_next_id();
+uint64_t session_get_next_id();
 
 /**
  * @brief Close a session
diff --git a/server/core/dcb.cc b/server/core/dcb.cc
index af83c99f7..b302b9579 100644
--- a/server/core/dcb.cc
+++ b/server/core/dcb.cc
@@ -163,7 +163,7 @@ static uint32_t dcb_process_poll_events(DCB *dcb, int thread_id, uint32_t ev);
 static void dcb_process_fake_events(DCB *dcb, int thread_id);
 static bool dcb_session_check(DCB *dcb, const char *);
 
-uint32_t dcb_get_session_id(DCB *dcb)
+uint64_t dcb_get_session_id(DCB *dcb)
 {
     return (dcb && dcb->session) ? dcb->session->ses_id : 0;
 }
@@ -1673,7 +1673,7 @@ dprintDCB(DCB *pdcb, DCB *dcb)
 
     if (dcb->session && dcb->session->state != SESSION_STATE_DUMMY)
     {
-        dcb_printf(pdcb, "\tOwning Session:     %" PRIu32 "\n", dcb->session->ses_id);
+        dcb_printf(pdcb, "\tOwning Session:     %" PRIu64 "\n", dcb->session->ses_id);
     }
 
     if (dcb->writeq)
diff --git a/server/core/session.cc b/server/core/session.cc
index 0ed98a34b..61d48bbe5 100644
--- a/server/core/session.cc
+++ b/server/core/session.cc
@@ -61,7 +61,7 @@ using std::stringstream;
 /** Global session id counter. Must be updated atomically. Value 0 is reserved for
  *  dummy/unused sessions.
  */
-static uint32_t next_session_id = 1;
+static uint64_t next_session_id = 1;
 
 static struct session session_dummy_struct;
 
@@ -162,7 +162,7 @@ MXS_SESSION* session_alloc(SERVICE *service, DCB *client_dcb)
     return session_alloc_body(service, client_dcb, session);
 }
 
-MXS_SESSION* session_alloc_with_id(SERVICE *service, DCB *client_dcb, uint32_t id)
+MXS_SESSION* session_alloc_with_id(SERVICE *service, DCB *client_dcb, uint64_t id)
 {
     MXS_SESSION *session = (MXS_SESSION *)(MXS_MALLOC(sizeof(*session)));
     if (session == NULL)
@@ -263,13 +263,13 @@ static MXS_SESSION* session_alloc_body(SERVICE* service, DCB* client_dcb,
 
         if (session->client_dcb->user == NULL)
         {
-            MXS_INFO("Started session [%" PRIu32 "] for %s service ",
+            MXS_INFO("Started session [%" PRIu64 "] for %s service ",
                      session->ses_id,
                      service->name);
         }
         else
         {
-            MXS_INFO("Started %s client session [%" PRIu32 "] for '%s' from %s",
+            MXS_INFO("Started %s client session [%" PRIu64 "] for '%s' from %s",
                      service->name,
                      session->ses_id,
                      session->client_dcb->user,
@@ -278,7 +278,7 @@ static MXS_SESSION* session_alloc_body(SERVICE* service, DCB* client_dcb,
     }
     else
     {
-        MXS_INFO("Start %s client session [%" PRIu32 "] for '%s' from %s failed, will be "
+        MXS_INFO("Start %s client session [%" PRIu64 "] for '%s' from %s failed, will be "
                  "closed as soon as all related DCBs have been closed.",
                  service->name,
                  session->ses_id,
@@ -448,7 +448,7 @@ static void session_free(MXS_SESSION *session)
         MXS_FREE(session->filters);
     }
 
-    MXS_INFO("Stopped %s client session [%" PRIu32 "]", session->service->name, session->ses_id);
+    MXS_INFO("Stopped %s client session [%" PRIu64 "]", session->service->name, session->ses_id);
 
     /** If session doesn't have parent referencing to it, it can be freed */
     if (!session->ses_is_child)
@@ -560,7 +560,7 @@ dprintSession(DCB *dcb, MXS_SESSION *print_session)
     char buf[30];
     int i;
 
-    dcb_printf(dcb, "Session %" PRIu32 "\n", print_session->ses_id);
+    dcb_printf(dcb, "Session %" PRIu64 "\n", print_session->ses_id);
     dcb_printf(dcb, "\tState:               %s\n", session_state(print_session->state));
     dcb_printf(dcb, "\tService:             %s\n", print_session->service->name);
 
@@ -600,7 +600,7 @@ bool dListSessions_cb(DCB *dcb, void *data)
     {
         DCB *out_dcb = (DCB*)data;
         MXS_SESSION *session = dcb->session;
-        dcb_printf(out_dcb, "%-16" PRIu32 " | %-15s | %-14s | %s\n", session->ses_id,
+        dcb_printf(out_dcb, "%-16" PRIu64 " | %-15s | %-14s | %s\n", session->ses_id,
                    session->client_dcb && session->client_dcb->remote ?
                    session->client_dcb->remote : "",
                    session->service && session->service->name ?
@@ -964,7 +964,7 @@ static bool ses_find_id(DCB *dcb, void *data)
 {
     void **params = (void**)data;
     MXS_SESSION **ses = (MXS_SESSION**)params[0];
-    uint32_t *id = (uint32_t*)params[1];
+    uint64_t *id = (uint64_t*)params[1];
     bool rval = true;
 
     if (dcb->session->ses_id == *id)
@@ -976,7 +976,7 @@ static bool ses_find_id(DCB *dcb, void *data)
     return rval;
 }
 
-MXS_SESSION* session_get_by_id(uint32_t id)
+MXS_SESSION* session_get_by_id(uint64_t id)
 {
     MXS_SESSION *session = NULL;
     void *params[] = {&session, &id};
@@ -1048,9 +1048,9 @@ void session_clear_stmt(MXS_SESSION *session)
     session->stmt.target = NULL;
 }
 
-uint32_t session_get_next_id()
+uint64_t session_get_next_id()
 {
-    return atomic_add_uint32(&next_session_id, 1);
+    return atomic_add_uint64(&next_session_id, 1);
 }
 
 void session_broadcast_kill_command(MXS_SESSION* issuer, uint64_t target_id)
diff --git a/server/modules/protocol/MySQL/MySQLClient/mysql_client.c b/server/modules/protocol/MySQL/MySQLClient/mysql_client.c
index fa684b277..0fca02133 100644
--- a/server/modules/protocol/MySQL/MySQLClient/mysql_client.c
+++ b/server/modules/protocol/MySQL/MySQLClient/mysql_client.c
@@ -241,9 +241,10 @@ int MySQLSendHandshake(DCB* dcb)
         memcpy(mysql_filler_ten + 6, &new_flags, sizeof(new_flags));
     }
 
-    // Get the equivalent of the server process id.
-    protocol->tid = session_get_next_id();
-    gw_mysql_set_byte4(mysql_thread_id_num, protocol->tid);
+    // Get the equivalent of the server thread id.
+    protocol->thread_id = session_get_next_id();
+    // Send only the low 32bits in the handshake.
+    gw_mysql_set_byte4(mysql_thread_id_num, (uint32_t)(protocol->thread_id));
     memcpy(mysql_scramble_buf, server_scramble, 8);
 
     memcpy(mysql_plugin_data, server_scramble + 8, 12);
@@ -668,7 +669,7 @@ gw_read_do_authentication(DCB *dcb, GWBUF *read_buffer, int nbytes_read)
          * normal data handling function instead of this one.
          */
         MXS_SESSION *session =
-            session_alloc_with_id(dcb->service, dcb, protocol->tid);
+            session_alloc_with_id(dcb->service, dcb, protocol->thread_id);
 
         if (session != NULL)
         {
diff --git a/server/modules/protocol/MySQL/mysql_common.c b/server/modules/protocol/MySQL/mysql_common.c
index 83e530db1..5e592f6d3 100644
--- a/server/modules/protocol/MySQL/mysql_common.c
+++ b/server/modules/protocol/MySQL/mysql_common.c
@@ -1410,7 +1410,6 @@ gw_decode_mysql_server_handshake(MySQLProtocol *conn, uint8_t *payload)
     uint8_t *server_version_end = NULL;
     uint16_t mysql_server_capabilities_one = 0;
     uint16_t mysql_server_capabilities_two = 0;
-    unsigned long tid = 0;
     uint8_t scramble_data_1[GW_SCRAMBLE_LENGTH_323] = "";
     uint8_t scramble_data_2[GW_MYSQL_SCRAMBLE_SIZE - GW_SCRAMBLE_LENGTH_323] = "";
     uint8_t capab_ptr[4] = "";
@@ -1433,8 +1432,10 @@ gw_decode_mysql_server_handshake(MySQLProtocol *conn, uint8_t *payload)
     payload = server_version_end + 1;
 
     // get ThreadID: 4 bytes
-    tid = gw_mysql_get_byte4(payload);
-    memcpy(&conn->tid, &tid, 4);
+    uint32_t tid = gw_mysql_get_byte4(payload);
+    /* TODO: Correct value of thread id could be queried later from backend if
+     * there is any worry it might be larger than 32bit allows. */
+    conn->thread_id = tid;
 
     payload += 4;
 
diff --git a/server/modules/routing/schemarouter/schemaroutersession.cc b/server/modules/routing/schemarouter/schemaroutersession.cc
index 64a10bd61..0bad5ecde 100644
--- a/server/modules/routing/schemarouter/schemaroutersession.cc
+++ b/server/modules/routing/schemarouter/schemaroutersession.cc
@@ -363,7 +363,7 @@ int32_t SchemaRouterSession::routeQuery(GWBUF* pPacket)
                 if (m_config->debug)
                 {
                     sprintf(errbuf + strlen(errbuf),
-                            " ([%" PRIu32 "]: DB change failed)",
+                            " ([%" PRIu64 "]: DB change failed)",
                             m_client->session->ses_id);
                 }
 
@@ -991,7 +991,7 @@ bool SchemaRouterSession::handle_default_db()
         sprintf(errmsg, "Unknown database '%s'", m_connect_db.c_str());
         if (m_config->debug)
         {
-            sprintf(errmsg + strlen(errmsg), " ([%" PRIu32 "]: DB not found on connect)",
+            sprintf(errmsg + strlen(errmsg), " ([%" PRIu64 "]: DB not found on connect)",
                     m_client->session->ses_id);
         }
         write_error_to_client(m_client,