diff --git a/uisimulator/win32/sprintf.h b/uisimulator/win32/sprintf.h
index 4e4bf25fc1..6e2b17f96a 100644
--- a/uisimulator/win32/sprintf.h
+++ b/uisimulator/win32/sprintf.h
@@ -26,6 +26,7 @@
 int snprintf (char *buf, size_t size, const char *fmt, ...);
 #ifndef NOCYGWIN
 int vsnprintf (char *buf, int size, const char *fmt, va_list ap);
+char *strtok_r (char *, const char *, char **);
 #endif
 
 #endif /* __SPRINTF_H__ */