diff --git a/test/end_to_end/recovery_SUITE.erl b/test/end_to_end/recovery_SUITE.erl
index 565ede8..8c63b04 100644
--- a/test/end_to_end/recovery_SUITE.erl
+++ b/test/end_to_end/recovery_SUITE.erl
@@ -175,7 +175,7 @@ aae_bustedjournal(_Config) ->
     testutil:corrupt_journal(RootPath, HeadF, 1000, 2048, 1000),
     {ok, Bookie2} = leveled_bookie:book_start(StartOpts),
     
-    FoldKeysFun = fun(B, K, Acc) -> Acc ++ [{B, K}] end,
+    FoldKeysFun = fun(B, K, Acc) -> [{B, K}|Acc] end,
     AllKeyQuery = {keylist, o_rkv, {FoldKeysFun, []}},
     {async, KeyF} = leveled_bookie:book_returnfolder(Bookie2, AllKeyQuery),
     KeyList = KeyF(),
diff --git a/test/end_to_end/testutil.erl b/test/end_to_end/testutil.erl
index 492b161..45b4a83 100644
--- a/test/end_to_end/testutil.erl
+++ b/test/end_to_end/testutil.erl
@@ -596,12 +596,12 @@ get_randomdate() ->
                                     [Year, Month, Day, Hour, Minute, Second])).
 
 
-foldkeysfun(_Bucket, Item, Acc) -> Acc ++ [Item].
+foldkeysfun(_Bucket, Item, Acc) -> [Item|Acc].
 
 foldkeysfun_returnbucket(Bucket, {Term, Key}, Acc) ->
-    Acc ++ [{Term, {Bucket, Key}}];
+    [{Term, {Bucket, Key}}|Acc];
 foldkeysfun_returnbucket(Bucket, Key, Acc) ->
-    Acc ++ [{Bucket, Key}].
+    [{Bucket, Key}|Acc].
 
 check_indexed_objects(Book, B, KSpecL, V) ->
     % Check all objects match, return what should be the results of an all