diff --git a/test/vhpi/issue978.c b/test/vhpi/issue978.c
index 930d8d878..33cc715bb 100644
--- a/test/vhpi/issue978.c
+++ b/test/vhpi/issue978.c
@@ -1,6 +1,7 @@
 #include "vhpi_test.h"
 
 #include <string.h>
+#include <stdint.h>
 
 static void test_period(void)
 {