diff --git a/docs/aeso_compiler.md b/docs/aeso_compiler.md
index 959529c..025ec45 100644
--- a/docs/aeso_compiler.md
+++ b/docs/aeso_compiler.md
@@ -51,8 +51,6 @@ The **pp_** options all print to standard output the following:
 
 `pp_assembler` - print the generated assembler code
 
-`pp_bytecode` - print the bytecode instructions
-
 #### check_call(ContractString, Options) -> CheckRet
 
 Types
diff --git a/src/aeso_ast_to_fcode.erl b/src/aeso_ast_to_fcode.erl
index 5194340..25802e0 100644
--- a/src/aeso_ast_to_fcode.erl
+++ b/src/aeso_ast_to_fcode.erl
@@ -363,7 +363,7 @@ to_fcode(Env, [{Contract, Attrs, Con = {con, _, Name}, Decls}|Rest])
             to_fcode(Env1, Rest)
     end;
 to_fcode(_Env, [NotMain = {NotMainHead, _ ,_ , _}]) when NotMainHead =/= contract_def ->
-    fcode_error({last_declaration_must_be_contract_def, NotMain});
+    fcode_error({last_declaration_must_be_main_contract, NotMain});
 to_fcode(Env, [{namespace, _, {con, _, Con}, Decls} | Code]) ->
     Env1 = decls_to_fcode(Env#{ context => {namespace, Con} }, Decls),
     to_fcode(Env1, Code).
diff --git a/src/aeso_code_errors.erl b/src/aeso_code_errors.erl
index ca8c692..269d8d7 100644
--- a/src/aeso_code_errors.erl
+++ b/src/aeso_code_errors.erl
@@ -49,12 +49,6 @@ format({invalid_aens_resolve_type, Ann, T}) ->
                         "It must be a string or a pubkey type (address, oracle, etc).",
                         [pp_type(2, T)]),
     mk_err(pos(Ann), Msg);
-format({invalid_map_key_type, Why, Ann, Type}) ->
-    Msg = io_lib:format("Invalid map key type\n~s", [pp_type(2, Type)]),
-    Cxt = case Why of
-             function    -> "Map keys cannot be higher-order."
-          end,
-    mk_err(pos(Ann), Msg, Cxt);
 format({invalid_oracle_type, Why, What, Ann, Type}) ->
     WhyS = case Why of higher_order -> "higher-order (contain function types)";
                        polymorphic  -> "polymorphic (contain type variables)" end,
diff --git a/src/aeso_compiler.erl b/src/aeso_compiler.erl
index 9d1905c..5580a7b 100644
--- a/src/aeso_compiler.erl
+++ b/src/aeso_compiler.erl
@@ -34,7 +34,6 @@
                 | pp_types
                 | pp_typed_ast
                 | pp_assembler
-                | pp_bytecode
                 | no_code
                 | keep_included
                 | debug_mode