diff --git a/apps/codecs.h b/apps/codecs.h
index 73a5709328..4d8c95eab0 100644
--- a/apps/codecs.h
+++ b/apps/codecs.h
@@ -198,7 +198,7 @@ struct codec_api {
     long* current_tick;
     long (*default_event_handler)(long event);
     long (*default_event_handler_ex)(long event, void (*callback)(void *), void *parameter);
-    int (*create_thread)(void* function, void* stack, int stack_size, const char *name);
+    int (*create_thread)(void (*function)(void), void* stack, int stack_size, const char *name);
     void (*remove_thread)(int threadnum);
     void (*reset_poweroff_timer)(void);
 #ifndef SIMULATOR
diff --git a/apps/plugin.h b/apps/plugin.h
index bbef2acb47..36eccfe86f 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -263,7 +263,7 @@ struct plugin_api {
     long* current_tick;
     long (*default_event_handler)(long event);
     long (*default_event_handler_ex)(long event, void (*callback)(void *), void *parameter);
-    int (*create_thread)(void* function, void* stack, int stack_size, const char *name);
+    int (*create_thread)(void (*function)(void), void* stack, int stack_size, const char *name);
     void (*remove_thread)(int threadnum);
     void (*reset_poweroff_timer)(void);
 #ifndef SIMULATOR
diff --git a/firmware/export/thread.h b/firmware/export/thread.h
index a7b5709deb..ad1b6527cd 100644
--- a/firmware/export/thread.h
+++ b/firmware/export/thread.h
@@ -24,7 +24,7 @@
 #define MAXTHREADS	10
 #define DEFAULT_STACK_SIZE 0x400 /* Bytes */
 
-int create_thread(void* function, void* stack, int stack_size,
+int create_thread(void (*function)(void), void* stack, int stack_size,
                   const char *name);
 void remove_thread(int threadnum);
 void switch_thread(void);
diff --git a/firmware/thread.c b/firmware/thread.c
index 7ddceaa9a1..d6a4a4f3db 100644
--- a/firmware/thread.c
+++ b/firmware/thread.c
@@ -261,7 +261,7 @@ void wake_up_thread(void)
  * Return ID if context area could be allocated, else -1.
  *---------------------------------------------------------------------------
  */
-int create_thread(void* function, void* stack, int stack_size,
+int create_thread(void (*function)(void), void* stack, int stack_size,
                   const char *name)
 {
     unsigned int i;
diff --git a/uisimulator/win32/thread-win32.c b/uisimulator/win32/thread-win32.c
index c2e9cef42b..ca973b6662 100644
--- a/uisimulator/win32/thread-win32.c
+++ b/uisimulator/win32/thread-win32.c
@@ -32,7 +32,7 @@ DWORD WINAPI runthread (LPVOID lpParameter)
     return 0;
 }
 
-int create_thread(void* fp, void* sp, int stk_size)
+int create_thread(void (*fp)(void), void* sp, int stk_size)
 {
     DWORD dwThreadID;
 
diff --git a/uisimulator/x11/thread.c b/uisimulator/x11/thread.c
index 4288c0ffcb..41f1fad8a7 100644
--- a/uisimulator/x11/thread.c
+++ b/uisimulator/x11/thread.c
@@ -101,7 +101,7 @@ void newfunc(void (*func)(void))
 }
 
 
-int create_thread(void* fp, void* sp, int stk_size)
+int create_thread(void (*fp)(void), void* sp, int stk_size)
 {
     pthread_t tid;
     int i;