diff --git a/c/tests/stress.c b/c/tests/stress.c
index 64cfa8e89c..0f6a5e05b7 100644
--- a/c/tests/stress.c
+++ b/c/tests/stress.c
@@ -75,7 +75,7 @@ static unsigned int get_random_seed(void)
     time_t t = time(NULL);
     struct tm timeinfo;
     localtime_safe(&timeinfo, &t);
-    int rc = strftime(buf, 10, "%y%W", &timeinfo);
+    size_t rc = strftime(buf, 10, "%y%W", &timeinfo);
     if (!rc)
         return 42;
     else