diff --git a/include/maxscale/messagequeue.hh b/include/maxscale/messagequeue.hh
index 1255e460d..0a1a8d578 100644
--- a/include/maxscale/messagequeue.hh
+++ b/include/maxscale/messagequeue.hh
@@ -195,7 +195,7 @@ private:
 
     uint32_t handle_poll_events(Worker* pWorker, uint32_t events);
 
-    static uint32_t poll_handler(MXB_POLL_DATA* pData, void* worker, uint32_t events);
+    static uint32_t poll_handler(MXB_POLL_DATA* pData, MXB_WORKER* worker, uint32_t events);
 
 private:
     Handler& m_handler;
diff --git a/include/maxscale/protocol/mariadb_client.hh b/include/maxscale/protocol/mariadb_client.hh
index 61f2d27d8..c83aa7995 100644
--- a/include/maxscale/protocol/mariadb_client.hh
+++ b/include/maxscale/protocol/mariadb_client.hh
@@ -60,7 +60,7 @@ public:
 private:
     static LocalClient* create(MYSQL_session* session, MySQLProtocol* proto, const char* ip, uint64_t port);
     LocalClient(MYSQL_session* session, MySQLProtocol* proto, int fd);
-    static uint32_t poll_handler(MXB_POLL_DATA* data, void* worker, uint32_t events);
+    static uint32_t poll_handler(MXB_POLL_DATA* data, MXB_WORKER* worker, uint32_t events);
     void   process(uint32_t events);
     GWBUF* read_complete_packet();
     void   drain_queue();
diff --git a/include/maxscale/worker.hh b/include/maxscale/worker.hh
index 394c2e5ba..0f3ce1d10 100644
--- a/include/maxscale/worker.hh
+++ b/include/maxscale/worker.hh
@@ -471,7 +471,7 @@ protected:
 private:
     uint32_t handle(Worker* pWorker, uint32_t events);
 
-    static uint32_t handler(MXB_POLL_DATA* pThis, void* pWorker, uint32_t events);
+    static uint32_t handler(MXB_POLL_DATA* pThis, MXB_WORKER* pWorker, uint32_t events);
 
 private:
     int     m_fd;      /**< The timerfd descriptor. */
diff --git a/maxutils/maxbase/include/maxbase/poll.h b/maxutils/maxbase/include/maxbase/poll.h
index 75657561c..bf4e6e662 100644
--- a/maxutils/maxbase/include/maxbase/poll.h
+++ b/maxutils/maxbase/include/maxbase/poll.h
@@ -43,13 +43,12 @@ typedef struct MXB_WORKER
  *
  * @return A combination of mxb_poll_action_t enumeration values.
  */
-// TODO: Change void* to MXS_WORKER
-typedef uint32_t (*mxb_poll_handler_t)(struct MXB_POLL_DATA* data, void* worker, uint32_t events);
+typedef uint32_t (*mxb_poll_handler_t)(struct MXB_POLL_DATA* data, MXB_WORKER* worker, uint32_t events);
 
 typedef struct MXB_POLL_DATA
 {
     mxb_poll_handler_t handler; /*< Handler for this particular kind of mxb_poll_data. */
-    void*              owner;   /*< Owning worker. */
+    MXB_WORKER*        owner;   /*< Owning worker. */
 } MXB_POLL_DATA;
 
 MXB_END_DECLS
diff --git a/server/core/dcb.cc b/server/core/dcb.cc
index aee7b8497..1d8066979 100644
--- a/server/core/dcb.cc
+++ b/server/core/dcb.cc
@@ -115,7 +115,7 @@ static bool dcb_add_to_worker(Worker* worker, DCB *dcb, uint32_t events);
 static DCB *dcb_find_free();
 static void dcb_remove_from_list(DCB *dcb);
 
-static uint32_t dcb_poll_handler(MXB_POLL_DATA *data, void* worker, uint32_t events);
+static uint32_t dcb_poll_handler(MXB_POLL_DATA *data, MXB_WORKER* worker, uint32_t events);
 static uint32_t dcb_process_poll_events(DCB *dcb, uint32_t ev);
 static bool dcb_session_check(DCB *dcb, const char *);
 static int upstream_throttle_callback(DCB *dcb, DCB_REASON reason, void *userdata);
@@ -342,7 +342,7 @@ dcb_free_all_memory(DCB *dcb)
     }
 
     // Ensure that id is immediately the wrong one.
-    dcb->poll.owner = reinterpret_cast<void*>(0xdeadbeef);
+    dcb->poll.owner = reinterpret_cast<MXB_WORKER*>(0xdeadbeef);
     MXS_FREE(dcb);
 
 }
@@ -3186,7 +3186,7 @@ static uint32_t dcb_handler(DCB* dcb, uint32_t events)
     return rv;
 }
 
-static uint32_t dcb_poll_handler(MXB_POLL_DATA *data, void* worker, uint32_t events)
+static uint32_t dcb_poll_handler(MXB_POLL_DATA *data, MXB_WORKER* worker, uint32_t events)
 {
     uint32_t rval = 0;
     DCB *dcb = (DCB*)data;
@@ -3409,7 +3409,7 @@ private:
 static bool add_fd_to_routing_workers(int fd, uint32_t events, MXB_POLL_DATA* data)
 {
     bool rv = true;
-    void* previous_owner = data->owner;
+    MXB_WORKER* previous_owner = data->owner;
 
     rv = RoutingWorker::add_shared_fd(fd, events, data);
 
diff --git a/server/core/internal/routingworker.hh b/server/core/internal/routingworker.hh
index aae1e05dc..b83adfafc 100644
--- a/server/core/internal/routingworker.hh
+++ b/server/core/internal/routingworker.hh
@@ -429,7 +429,7 @@ private:
 
     void delete_zombies();
 
-    static uint32_t epoll_instance_handler(MXB_POLL_DATA* data, void* worker, uint32_t events);
+    static uint32_t epoll_instance_handler(MXB_POLL_DATA* data, MXB_WORKER* worker, uint32_t events);
     uint32_t handle_epoll_events(uint32_t events);
 };
 
diff --git a/server/core/messagequeue.cc b/server/core/messagequeue.cc
index 46cee14a7..78183fde5 100644
--- a/server/core/messagequeue.cc
+++ b/server/core/messagequeue.cc
@@ -315,7 +315,7 @@ uint32_t MessageQueue::handle_poll_events(Worker* pWorker, uint32_t events)
 }
 
 //static
-uint32_t MessageQueue::poll_handler(MXB_POLL_DATA* pData, void* pWorker, uint32_t events)
+uint32_t MessageQueue::poll_handler(MXB_POLL_DATA* pData, MXB_WORKER* pWorker, uint32_t events)
 {
     MessageQueue* pThis = static_cast<MessageQueue*>(pData);
 
diff --git a/server/core/routingworker.cc b/server/core/routingworker.cc
index 25e6e42b0..3db5012b9 100644
--- a/server/core/routingworker.cc
+++ b/server/core/routingworker.cc
@@ -544,7 +544,7 @@ void RoutingWorker::epoll_tick()
  * @return What actions were performed.
  */
 //static
-uint32_t RoutingWorker::epoll_instance_handler(MXB_POLL_DATA* pData, void* pWorker, uint32_t events)
+uint32_t RoutingWorker::epoll_instance_handler(MXB_POLL_DATA* pData, MXB_WORKER* pWorker, uint32_t events)
 {
     RoutingWorker* pThis = static_cast<RoutingWorker*>(pData);
     ss_dassert(pThis == pWorker);
diff --git a/server/core/worker.cc b/server/core/worker.cc
index 8d6618582..33bb9a78f 100644
--- a/server/core/worker.cc
+++ b/server/core/worker.cc
@@ -255,7 +255,7 @@ uint32_t WorkerTimer::handle(Worker* pWorker, uint32_t events)
 }
 
 //static
-uint32_t WorkerTimer::handler(MXB_POLL_DATA* pThis, void* pWorker, uint32_t events)
+uint32_t WorkerTimer::handler(MXB_POLL_DATA* pThis, MXB_WORKER* pWorker, uint32_t events)
 {
     return static_cast<WorkerTimer*>(pThis)->handle(static_cast<Worker*>(pWorker), events);
 }
diff --git a/server/modules/protocol/MySQL/mariadb_client.cc b/server/modules/protocol/MySQL/mariadb_client.cc
index 661ed8988..2ab5ff674 100644
--- a/server/modules/protocol/MySQL/mariadb_client.cc
+++ b/server/modules/protocol/MySQL/mariadb_client.cc
@@ -225,7 +225,7 @@ void LocalClient::drain_queue()
     }
 }
 
-uint32_t LocalClient::poll_handler(MXB_POLL_DATA* data, void* worker, uint32_t events)
+uint32_t LocalClient::poll_handler(MXB_POLL_DATA* data, MXB_WORKER* worker, uint32_t events)
 {
     LocalClient* client = static_cast<LocalClient*>(data);
     client->process(events);