diff --git a/m-array.h b/m-array.h
index a4eb7242..0aeff9d5 100644
--- a/m-array.h
+++ b/m-array.h
@@ -218,7 +218,7 @@
   }                                                                     \
   									\
   static inline void                                                    \
-  M_C(name, _set_at)(array_t v, size_t i, type x)			\
+  M_C(name, _set_at)(array_t v, size_t i, type const x)			\
   {                                                                     \
     ARRAYI_CONTRACT(v);                                                 \
     assert(v->size > 0 && v->ptr != NULL && i < v->size);               \
diff --git a/tests/test-mconcurrent.c b/tests/test-mconcurrent.c
index 76f0d86b..2626763d 100644
--- a/tests/test-mconcurrent.c
+++ b/tests/test-mconcurrent.c
@@ -78,6 +78,9 @@ TUPLE_DEF2(my_tuple, (pool, string_pool_ts_t))
 #define MY_TUPLE_OPLIST TUPLE_OPLIST(my_tuple, STRING_POOL_TS_OPLIST)
 #define M_OPL_my_tuple_t() MY_TUPLE_OPLIST
 
+ARRAY_DEF(key_list, string_t)
+#define M_OPL_key_list_t() ARRAY_OPLIST(key_list, STRING_OPLIST)
+CONCURRENT_DEF(key_list_ts, key_list_t)
 
 CONCURRENT_RP_DEF(rpdict1, dict1_t, DICT_OPLIST(dict1))