diff --git a/test/test-utils.c b/test/test-utils.c
index 55a2e156..7c938b0a 100644
--- a/test/test-utils.c
+++ b/test/test-utils.c
@@ -1445,7 +1445,7 @@ END_TEST
 struct atou64_test {
 	char *str;
 	bool success;
-	unsigned long val;
+	uint64_t val;
 };
 
 START_TEST(safe_atou64_test)