diff --git a/library/timing.c b/library/timing.c
index 913cbdc..5791ef4 100644
--- a/library/timing.c
+++ b/library/timing.c
@@ -254,7 +254,7 @@
 /* It's OK to use a global because alarm() is supposed to be global anyway */
 static DWORD alarmMs;
 
-DWORD WINAPI TimerProc( LPVOID TimerContext )
+static DWORD WINAPI TimerProc( LPVOID TimerContext )
 {
     ((void) TimerContext);
     Sleep( alarmMs );