diff --git a/src/hbbft.erl b/src/hbbft.erl
index ceac94e..fd6a782 100644
--- a/src/hbbft.erl
+++ b/src/hbbft.erl
@@ -139,7 +139,7 @@ start_on_demand(Data) ->
 -spec input(hbbft_data(), binary()) -> {hbbft_data(), ok | {send, [rbc_wrapped_output()]} | full}.
 input(Data = #hbbft_data{buf=Buf, max_buf=MaxBuf}, Txn) when is_binary(Txn), length(Buf) < MaxBuf->
     %% add this txn to the the buffer
-    NewBuf = [Txn | Buf],
+    NewBuf = Buf ++ [Txn],
     maybe_start_acs(Data#hbbft_data{buf=NewBuf});
 input(Data = #hbbft_data{buf=_Buf}, _Txn) when is_binary(_Txn) ->
     %% drop the txn