diff --git a/tests/test-mlist.c b/tests/test-mlist.c
index af3926bd..40f26bf7 100644
--- a/tests/test-mlist.c
+++ b/tests/test-mlist.c
@@ -107,6 +107,7 @@ static void test_uint(void)
   list_uint_t v2;
   list_it_uint_t u2;
   list_uint_init(v2);
+  list_uint_set(v, v);
   list_uint_set(v2,v);
   for(list_uint_it(u, v), list_uint_it(u2, v2); !list_uint_end_p(u); list_uint_next(u), list_uint_next(u2)) {
     assert(list_uint_end_p(u2) == false);
diff --git a/tests/test-mstring.c b/tests/test-mstring.c
index a14b490a..9d5bb50c 100644
--- a/tests/test-mstring.c
+++ b/tests/test-mstring.c
@@ -77,7 +77,8 @@ int main(void)
   assert (i == 7);
   i = string_search_str (s1, "World");
   assert (i == STRING_FAILURE);
-  
+
+  string_set (s1, s1);
   string_set (s2, s1);
 
   j = string_search_char (s1, ',');