diff --git a/m-algo.h b/m-algo.h
index 30762028..cf8fb12a 100644
--- a/m-algo.h
+++ b/m-algo.h
@@ -75,13 +75,30 @@
 
 /* Define, initialize, set & clear a container with a variable array list.
    USAGE:
-   ALGO_LET_INIT_VA(container, containerOplist, param1[, param2[, ...]]) {
-        // Stuff with container
+   ALGO_LET_INIT_VA(container, containerOplist|type, param1[, param2[, ...]]) {
+   // Stuff with container
    } */
 #define ALGO_LET_INIT_VA(dest, contOp, ...)                     \
   ALGO_LET_INIT_VAI(dest, M_GLOBAL_OPLIST(contOp), __VA_ARGS__)
 
 
+#define ALGO_INSERT_AT(contDst, contDstOp, position, contSrc, contSrcOp) \
+  ALGOI_INSERT_AT(contDst, M_GLOBAL_OPLIST(contDstOp), position, contSrc, M_GLOBAL_OPLIST(contSrcOp) )
+
+#define ALGOI_INSERT_AT(contDst, contDstOp, position, contSrc, contSrcOp) do { \
+    M_GET_IT_TYPE contSrcOp itSrc;                                      \
+    M_GET_IT_TYPE contDstOp itDst;                                      \
+    M_GET_IT_SET contDstOp (itDst, position);                           \
+    for (M_GET_IT_FIRST contSrcOp (itSrc, contSrc) ;                    \
+         !M_GET_IT_END_P contSrcOp (itSrc) ;                            \
+         M_GET_IT_NEXT contSrcOp (itSrc) ) {                            \
+      M_GET_IT_INSERT contDstOp (contDst, itDst,                        \
+                                 *M_GET_IT_CREF contSrcOp (itSrc));     \
+      M_GET_IT_NEXT contDstOp (itDst);                                  \
+    }                                                                   \
+  } while (0)
+
+
 /********************************** INTERNAL ************************************/
 
 #define ALGOI_DEF(name, cont_oplist)                                    \
@@ -668,7 +685,7 @@
       }									\
     }									\
     while (!M_GET_IT_END_P cont_oplist (itSrc)) {			\
-      type *objSrc = M_GET_REF cont_oplist (itSrc);			\
+      type_t *objSrc = M_GET_IT_REF cont_oplist (itSrc);                \
       M_GET_PUSH cont_oplist (dst, *objSrc);				\
       M_GET_IT_NEXT cont_oplist (itSrc);				\
     }									\
diff --git a/tests/test-malgo.c b/tests/test-malgo.c
index b630d125..a3b49fa2 100644
--- a/tests/test-malgo.c
+++ b/tests/test-malgo.c
@@ -386,11 +386,31 @@ static void test_extract(void)
   list_int_clear(l);
 }
 
+ARRAY_DEF(aint, int)
+LIST_DEF(lint, int)
+#define M_OPL_aint_t() ARRAY_OPLIST(aint)
+#define M_OPL_lint_t() LIST_OPLIST(lint)
+
+static void test_insert(void)
+{
+  ALGO_LET_INIT_VA(a, lint_t, 1, 2, 3, 4)
+    ALGO_LET_INIT_VA(b, aint_t, -1, -2, -3) {
+    lint_it_t i;
+    lint_it(i, a);
+    ALGO_INSERT_AT(a, lint_t, i, b, aint_t);
+    // TBC: order ok for the list (the reverse is confusing...)?
+    ALGO_LET_INIT_VA(c, lint_t, 1, 2, 3, -3, -2, -1, 4) {
+      assert (lint_equal_p (c, a));
+    }
+  }
+}
+
 int main(void)
 {
   test_list();
   test_array();
   test_string();
   test_extract();
+  test_insert();
   exit(0);
 }