diff --git a/obexd/plugins/messages-tracker.c b/obexd/plugins/messages-tracker.c
index 218a016..8f9b30a 100644
--- a/obexd/plugins/messages-tracker.c
+++ b/obexd/plugins/messages-tracker.c
@@ -120,7 +120,7 @@ static void destroy_folder_tree(void *root)
 	g_free(folder);
 }
 
-static void create_folder_tree()
+static void create_folder_tree(void)
 {
 	struct message_folder *parent, *child;
 
diff --git a/obexd/src/log.c b/obexd/src/log.c
index baa57c5..db7b5f3 100644
--- a/obexd/src/log.c
+++ b/obexd/src/log.c
@@ -92,7 +92,7 @@ static gboolean is_enabled(struct obex_debug_desc *desc)
 	return 0;
 }
 
-void __obex_log_enable_debug()
+void __obex_log_enable_debug(void)
 {
 	struct obex_debug_desc *desc;
 
diff --git a/obexd/src/manager.c b/obexd/src/manager.c
index db5d67d..3953e9d 100644
--- a/obexd/src/manager.c
+++ b/obexd/src/manager.c
@@ -450,7 +450,7 @@ void manager_unregister_transfer(struct obex_session *os)
 	g_free(path);
 }
 
-static void agent_cancel()
+static void agent_cancel(void)
 {
 	DBusMessage *msg;
 
diff --git a/obexd/src/transport.c b/obexd/src/transport.c
index 6d51f53..f178e44 100644
--- a/obexd/src/transport.c
+++ b/obexd/src/transport.c
@@ -53,7 +53,7 @@ static struct obex_transport_driver *obex_transport_driver_find(
 	return NULL;
 }
 
-GSList *obex_transport_driver_list()
+GSList *obex_transport_driver_list(void)
 {
 	return drivers;
 }