diff --git a/src/folsom_metrics_history.erl b/src/folsom_metrics_history.erl
index 6913063..2aee7c9 100644
--- a/src/folsom_metrics_history.erl
+++ b/src/folsom_metrics_history.erl
@@ -78,6 +78,6 @@ get_prev_event(_, '$end_of_table', _, Acc) ->
     Acc;
 get_prev_event(Name, Key, Count, Acc) when length(Acc) < Count ->
     Event = ets:lookup(Name, Key),
-    get_prev_event(Name, ets:prev(Name, Key), Count, lists:append(Acc, Event));
+    get_prev_event(Name, ets:prev(Name, Key), Count, Acc ++ Event);
 get_prev_event(_, _, _, Acc) ->
     Acc.
diff --git a/src/folsom_vm_metrics.erl b/src/folsom_vm_metrics.erl
index 1adc5b0..66c9a54 100644
--- a/src/folsom_vm_metrics.erl
+++ b/src/folsom_vm_metrics.erl
@@ -146,15 +146,15 @@ convert_c_compiler_version(A) ->
     list_to_binary(io_lib:format("~p", [A])).
 
 convert_cpu_topology([{core, Value}| Tail], Acc) when is_tuple(Value) ->
-    convert_cpu_topology(Tail, lists:append(Acc, [{core, tuple_to_list(Value)}]));
+    convert_cpu_topology(Tail, Acc ++ [{core, tuple_to_list(Value)}]);
 convert_cpu_topology([{core, Value}| Tail], Acc) when is_list(Value) ->
-    convert_cpu_topology(Tail, lists:append(Acc, [{core, convert_cpu_topology(Value, [])}]));
+    convert_cpu_topology(Tail, Acc ++ [{core, convert_cpu_topology(Value, [])}]);
 convert_cpu_topology([{thread, Value}| Tail], Acc) ->
-    convert_cpu_topology(Tail, lists:append(Acc, [{thread, tuple_to_list(Value)}]));
+    convert_cpu_topology(Tail, Acc ++ [{thread, tuple_to_list(Value)}]);
 convert_cpu_topology([{node, Value}| Tail], Acc) ->
-    convert_cpu_topology(Tail, lists:append(Acc, [{node, convert_cpu_topology(Value, [])}]));
+    convert_cpu_topology(Tail, Acc ++ [{node, convert_cpu_topology(Value, [])}]);
 convert_cpu_topology([{processor, Value}| Tail], Acc) ->
-    convert_cpu_topology(Tail, lists:append(Acc, [{processor, convert_cpu_topology(Value, [])}]));
+    convert_cpu_topology(Tail, Acc ++ [{processor, convert_cpu_topology(Value, [])}]);
 convert_cpu_topology({Key, Value}, _) ->
     [{Key, Value}];
 convert_cpu_topology([], Acc) ->