diff --git a/compiler/heptagon/transformations/inline.ml b/compiler/heptagon/transformations/inline.ml
index 1a6857f..8f4a798 100644
--- a/compiler/heptagon/transformations/inline.ml
+++ b/compiler/heptagon/transformations/inline.ml
@@ -46,6 +46,12 @@ let mk_unique_node nd =
   fst (Hept_mapfold.node_dec funs () nd)
 
 let exp funs (env, newvars, newequs) exp = match exp.e_desc with
+  | Eiterator (it, { a_op = Enode nn; }, _, _, _) when to_be_inlined nn ->
+      Printf.eprintf
+        "WARN: inlining iterators (\"%s %s\" here) is unsupported.\n"
+        (Hept_printer.iterator_to_string it) (fullname nn);
+      (exp, (env, newvars, newequs))
+
   | Eapp ({ a_op = Enode nn; } as op, argl, rso) when to_be_inlined nn ->
       let add_reset eq = match rso with
         | None -> eq