diff --git a/src/lib/empthread/ntthread.c b/src/lib/empthread/ntthread.c
index ce5c7fb1..e82a2a88 100644
--- a/src/lib/empthread/ntthread.c
+++ b/src/lib/empthread/ntthread.c
@@ -58,6 +58,7 @@
 #include <process.h>
 #include "misc.h"
 #include "empthread.h"
+#include "prototypes.h"
 
 #define loc_MIN_THREAD_STACK  16384