diff --git a/src/proto_alpha/lib_client/injection.ml b/src/proto_alpha/lib_client/injection.ml
index b02bcb69a..b84562c92 100644
--- a/src/proto_alpha/lib_client/injection.ml
+++ b/src/proto_alpha/lib_client/injection.ml
@@ -377,7 +377,13 @@ let inject_operation
     cctxt#message "Operation hash: %a" Operation_hash.pp oph >>= fun () ->
     begin
       match confirmations with
-      | None -> return result
+      | None ->
+          cctxt#message "@[<v 0>NOT waiting for the operation to be included.@,\
+                         Use command@,\
+                        \  tezos-client wait for %a to be included --confirmations 30@,\
+                         and/or an external block explorer to make sure that it has been included.@]"
+            Operation_hash.pp oph >>= fun () ->
+          return result
       | Some confirmations ->
           cctxt#message "Waiting for the operation to be included..." >>= fun () ->
           Client_confirmations.wait_for_operation_inclusion
@@ -405,6 +411,22 @@ let inject_operation
            "New contract %a originated."
            Contract.pp c)
       contracts >>= fun () ->
+    begin match confirmations with
+      | None -> Lwt.return_unit
+      | Some number ->
+          if number >= 30 then
+            cctxt#message
+              "The operation was included in a block %d blocks ago."
+              number
+          else
+            cctxt#message
+              "@[<v 0>The operation has only been included %d blocks ago.@,\
+               We recommend to wait more.@,\
+               Use command@,\
+              \  tezos-client wait for %a to be included --confirmations 30@,\
+               and/or an external block explorer.@]"
+              number Operation_hash.pp oph
+    end >>= fun () ->
     return (oph, op.protocol_data.contents, result.contents)
 
 let inject_manager_operation