diff --git a/src/core/ft/ft.c b/src/core/ft/ft.c
index 2e64e4c..1abebc9 100644
--- a/src/core/ft/ft.c
+++ b/src/core/ft/ft.c
@@ -635,7 +635,8 @@ LIB3270_EXPORT LIB3270_FT_STATE lib3270_get_ft_state(H3270 *session) {
 	return ((H3270FT *) session->ft)->state;
 }
 
-LIB3270_EXPORT int lib3270_send(H3270 *hSession, const char *from, const char *to, const char **args) {
+LIB3270_EXPORT int lib3270_send(H3270 *hSession, const char GNUC_UNUSED(*from), const char GNUC_UNUSED(*to), const char GNUC_UNUSED(**args)) {
+
 	FAIL_IF_NOT_ONLINE(hSession);
 
 	if(hSession->ft)
@@ -644,7 +645,7 @@ LIB3270_EXPORT int lib3270_send(H3270 *hSession, const char *from, const char *t
 	return ENOTSUP;
 }
 
-LIB3270_EXPORT int lib3270_receive(H3270 *hSession, const char *from, const char *to, const char **args) {
+LIB3270_EXPORT int lib3270_receive(H3270 *hSession, const char GNUC_UNUSED(*from), const char GNUC_UNUSED(*to), const char GNUC_UNUSED(**args)) {
 	FAIL_IF_NOT_ONLINE(hSession);
 
 	if(hSession->ft)
diff --git a/src/core/linux/log.c b/src/core/linux/log.c
index de9be14..697dd74 100644
--- a/src/core/linux/log.c
+++ b/src/core/linux/log.c
@@ -42,7 +42,7 @@
 
 int use_syslog = 0;
 
-int default_log_writer(H3270 GNUC_UNUSED(*session), void GNUC_UNUSED(*userdata), const char *module, int GNUC_UNUSED(rc), const char *message) {
+int default_log_writer(const H3270 GNUC_UNUSED(*session), void GNUC_UNUSED(*userdata), const char *module, int GNUC_UNUSED(rc), const char *message) {
 #ifdef HAVE_SYSLOG
 	if(use_syslog) {
 		syslog(LOG_INFO, "%s: %s", module, message);
diff --git a/src/core/log.c b/src/core/log.c
index 081963f..0eb65e8 100644
--- a/src/core/log.c
+++ b/src/core/log.c
@@ -120,9 +120,10 @@ LIB3270_EXPORT int lib3270_set_log_filename(H3270 * hSession, const char *filena
 
 }
 
-LIB3270_EXPORT void lib3270_set_log_handler(H3270 *session, const LIB3270_LOG_HANDLER handler) {
+LIB3270_EXPORT void lib3270_set_log_handler(H3270 *session, const LIB3270_LOG_HANDLER handler, void *userdata) {
 	if(session) {
 		session->log.handler = (handler ? handler : default_log_writer);
+		session->log.userdata = userdata;
 	} else {
 		loghandler = (handler ? handler : default_log_writer);
 	}
diff --git a/src/core/windows/log.c b/src/core/windows/log.c
index f1c1213..4e0cf1b 100644
--- a/src/core/windows/log.c
+++ b/src/core/windows/log.c
@@ -41,9 +41,10 @@
 
 /*---[ Implement ]------------------------------------------------------------------------------------------*/
 
-int default_log_writer(H3270 GNUC_UNUSED(*session), const char *module, int rc, const char *msg) {
+int default_log_writer(const H3270 GNUC_UNUSED(*session), void GNUC_UNUSED(*userdata), const char *module, int rc, const char *msg) {
 
 	if(hEventLog) {
+
 		lib3270_autoptr(char) username = lib3270_get_user_name();
 
 		const char *outMsg[] = {
diff --git a/src/include/internals.h b/src/include/internals.h
index b25e34a..e4e6e2b 100644
--- a/src/include/internals.h
+++ b/src/include/internals.h
@@ -740,7 +740,7 @@ LIB3270_INTERNAL void clear_chr(H3270 *hSession, int baddr);
 LIB3270_INTERNAL unsigned char get_field_attribute(H3270 *session, int baddr);
 
 /// @brief Default log writer.
-LIB3270_INTERNAL int default_log_writer(H3270 *session, void *dunno, const char *module, int rc, const char *message);
+LIB3270_INTERNAL int default_log_writer(const H3270 *session, void *dunno, const char *module, int rc, const char *message);
 
 /// @brief The active log handler.
 LIB3270_INTERNAL LIB3270_LOG_HANDLER loghandler;
diff --git a/src/include/lib3270/log.h b/src/include/lib3270/log.h
index 04773c2..7e5d906 100644
--- a/src/include/lib3270/log.h
+++ b/src/include/lib3270/log.h
@@ -54,7 +54,7 @@ extern "C" {
 
 typedef int (*LIB3270_LOG_HANDLER)(const H3270 *, void *, const char *, int, const char *);
 
-LIB3270_EXPORT void	  lib3270_set_log_handler(H3270 *session, const LIB3270_LOG_HANDLER loghandler);
+LIB3270_EXPORT void	  lib3270_set_log_handler(H3270 *session, const LIB3270_LOG_HANDLER loghandler, void *userdata);
 LIB3270_EXPORT int	  lib3270_set_log_filename(H3270 * hSession, const char *name);
 LIB3270_EXPORT const char * lib3270_get_log_filename(const H3270 * hSession);
 
--
libgit2 0.21.2