Fixes for missing prototypes warnings.
diff --git a/loader/kthread.c b/loader/kthread.c
index e27eb2e..eb612a7 100644
--- a/loader/kthread.c
+++ b/loader/kthread.c
@@ -564,7 +564,7 @@
 
 static pthread_mutex_t atfork_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-typedef void (*atfork_handler)();
+typedef void (*atfork_handler)(void);
 static atfork_handler atfork_prepare[MAX_ATFORK];
 static atfork_handler atfork_parent[MAX_ATFORK];
 static atfork_handler atfork_child[MAX_ATFORK];