diff --git a/dbus/controller_iface_control.c b/dbus/controller_iface_control.c
index ffed3e3c..cb478a98 100644
--- a/dbus/controller_iface_control.c
+++ b/dbus/controller_iface_control.c
@@ -35,7 +35,7 @@
 #define JACK_DBUS_IFACE_NAME "org.jackaudio.JackControl"
 
 void
-jack_controller_control_send_signal_server_started()
+jack_controller_control_send_signal_server_started(void)
 {
 
     jack_dbus_send_signal(
@@ -46,7 +46,7 @@ jack_controller_control_send_signal_server_started()
 }
 
 void
-jack_controller_control_send_signal_server_stopped()
+jack_controller_control_send_signal_server_stopped(void)
 {
 
     jack_dbus_send_signal(
diff --git a/dbus/controller_iface_introspectable.c b/dbus/controller_iface_introspectable.c
index 8b1a644c..95d651f9 100644
--- a/dbus/controller_iface_introspectable.c
+++ b/dbus/controller_iface_introspectable.c
@@ -75,10 +75,10 @@ write_line(const char * line)
     write_line_format("%s\n", line);
 }
 
-void jack_controller_introspect_init() __attribute__((constructor));
+void jack_controller_introspect_init(void) __attribute__((constructor));
 
 void
-jack_controller_introspect_init()
+jack_controller_introspect_init(void)
 {
     struct jack_dbus_interface_descriptor ** interface_ptr_ptr;
     const struct jack_dbus_interface_method_descriptor * method_ptr;
diff --git a/dbus/jackdbus.c b/dbus/jackdbus.c
index c85ae3a1..b6e2698d 100644
--- a/dbus/jackdbus.c
+++ b/dbus/jackdbus.c
@@ -695,7 +695,7 @@ pathname_cat(const char *pathname_a, const char *pathname_b)
 }
 
 bool
-paths_init()
+paths_init(void)
 {
 	const char *home_dir, *xdg_config_home, *xdg_log_home;
     
@@ -748,7 +748,7 @@ fail:
 }
 
 void
-paths_uninit()
+paths_uninit(void)
 {
     free(g_jackdbus_config_dir);
     free(g_jackdbus_log_dir);
diff --git a/dbus/jackdbus.h b/dbus/jackdbus.h
index c0ab8861..b7c050b6 100644
--- a/dbus/jackdbus.h
+++ b/dbus/jackdbus.h
@@ -39,10 +39,10 @@ extern size_t g_jackdbus_config_dir_len; /* without terminating '\0' char */
 extern int g_exit_command;
 
 bool
-jack_controller_settings_init();
+jack_controller_settings_init(void);
 
 void
-jack_controller_settings_uninit();
+jack_controller_settings_uninit(void);
 
 #define JACK_DBUS_ERROR_UNKNOWN_METHOD              "org.jackaudio.Error.UnknownMethod"
 #define JACK_DBUS_ERROR_SERVER_NOT_RUNNING          "org.jackaudio.Error.ServerNotRunning"
diff --git a/dbus/xml_expat.c b/dbus/xml_expat.c
index f5a5aa68..74177dfb 100644
--- a/dbus/xml_expat.c
+++ b/dbus/xml_expat.c
@@ -37,13 +37,13 @@
 #include "jackdbus.h"
 
 bool
-jack_controller_settings_init()
+jack_controller_settings_init(void)
 {
     return true;
 }
 
 void
-jack_controller_settings_uninit()
+jack_controller_settings_uninit(void)
 {
 }
 
diff --git a/dbus/xml_write_raw.c b/dbus/xml_write_raw.c
index 3ef13997..6006b866 100644
--- a/dbus/xml_write_raw.c
+++ b/dbus/xml_write_raw.c
@@ -42,7 +42,7 @@ jack_controller_settings_write_string(int fd, const char * string, void *dbus_ca
 
     len = strlen(string);
 
-    if (write(fd, string, len) != len)
+    if (write(fd, string, len) != (ssize_t)len)
     {
         jack_dbus_error(dbus_call_context_ptr, JACK_DBUS_ERROR_GENERIC, "write() failed to write config file.");
         return false;