diff --git a/src/plist.c b/src/plist.c
index f03e125..454d08c 100644
--- a/src/plist.c
+++ b/src/plist.c
@@ -69,10 +69,10 @@
     int state;
 } thread_once_t;
 
-static const thread_once_t init_once = {0, 0};
-static const thread_once_t deinit_once = {0, 0};
+static thread_once_t init_once = {0, 0};
+static thread_once_t deinit_once = {0, 0};
 
-void thread_once(thread_once_t *once_control, void (*init_routine)(void))
+static void thread_once(thread_once_t *once_control, void (*init_routine)(void))
 {
     while (InterlockedExchange(&(once_control->lock), 1) != 0) {
         Sleep(1);