diff --git a/lib/elixir/src/elixir_parser.yrl b/lib/elixir/src/elixir_parser.yrl
index ff05f97c4c..88c1f5a117 100644
--- a/lib/elixir/src/elixir_parser.yrl
+++ b/lib/elixir/src/elixir_parser.yrl
@@ -696,7 +696,7 @@ unwrap_when(Args) ->
       Args
   end.
 
-to_block([One]) when not is_list(One) -> One;
+to_block([One]) -> One;
 to_block(Other) -> {'__block__', [], reverse(Other)}.
 
 %% Errors