diff --git a/etc/mont.c b/etc/mont.c
index e42c52b..368b1ca 100644
--- a/etc/mont.c
+++ b/etc/mont.c
@@ -1,5 +1,6 @@
 /* tests the montgomery routines */
 #include <tommath.h>
+#include <time.h>
 
 int main(void)
 {