diff --git a/lark/common.py b/lark/common.py
index 76155f3..9c18972 100644
--- a/lark/common.py
+++ b/lark/common.py
@@ -8,9 +8,9 @@ class LexerConf:
         self.callbacks = callbacks or {}
 
 class ParserConf:
-    def __init__(self, rules, callback, start):
+    def __init__(self, rules, callbacks, start):
         self.rules = rules
-        self.callback = callback
+        self.callbacks = callbacks
         self.start = start
 
 
diff --git a/lark/lark.py b/lark/lark.py
index 4445e6f..178141c 100644
--- a/lark/lark.py
+++ b/lark/lark.py
@@ -132,7 +132,7 @@ class Lark:
             raise NotImplementedError("Not available yet")
 
         assert not self.options.profile, "Feature temporarily disabled"
-        self.profiler = Profiler() if self.options.profile else None
+        # self.profiler = Profiler() if self.options.profile else None
 
         if self.options.lexer == 'auto':
             if self.options.parser == 'lalr':
@@ -192,8 +192,6 @@ class Lark:
         elif lexer:
             self.lexer = self._build_lexer()
 
-        if self.profiler: self.profiler.enter_section('outside_lark')
-
     if __init__.__doc__:
         __init__.__doc__ += "\nOPTIONS:" + LarkOptions.OPTIONS_DOC
 
@@ -204,13 +202,9 @@ class Lark:
         self.parser_class = get_frontend(self.options.parser, self.options.lexer)
 
         self._parse_tree_builder = ParseTreeBuilder(self.rules, self.options.tree_class, self.options.propagate_positions, self.options.keep_all_tokens, self.options.parser!='lalr' and self.options.ambiguity=='explicit', self.options.maybe_placeholders)
-        callback = self._parse_tree_builder.create_callback(self.options.transformer)
-        if self.profiler:
-            for f in dir(callback):
-                if not (f.startswith('__') and f.endswith('__')):
-                    setattr(callback, f, self.profiler.make_wrapper('transformer', getattr(callback, f)))
+        callbacks = self._parse_tree_builder.create_callback(self.options.transformer)
 
-        parser_conf = ParserConf(self.rules, callback, self.options.start)
+        parser_conf = ParserConf(self.rules, callbacks, self.options.start)
 
         return self.parser_class(self.lexer_conf, parser_conf, options=self.options)
 
diff --git a/lark/parse_tree_builder.py b/lark/parse_tree_builder.py
index 97189b6..ca12d5f 100644
--- a/lark/parse_tree_builder.py
+++ b/lark/parse_tree_builder.py
@@ -187,10 +187,6 @@ def maybe_create_ambiguous_expander(tree_class, expansion, keep_all_tokens):
     if to_expand:
         return partial(AmbiguousExpander, to_expand, tree_class)
 
-class Callback(object):
-    pass
-
-
 def ptb_inline_args(func):
     @wraps(func)
     def f(children):
@@ -207,8 +203,6 @@ class ParseTreeBuilder:
 
         self.rule_builders = list(self._init_builders(rules))
 
-        self.user_aliases = {}
-
     def _init_builders(self, rules):
         for rule in rules:
             options = rule.options
@@ -226,12 +220,9 @@ class ParseTreeBuilder:
 
 
     def create_callback(self, transformer=None):
-        callback = Callback()
+        callbacks = {}
 
-        i = 0
         for rule, wrapper_chain in self.rule_builders:
-            internal_callback_name = '_cb%d_%s' % (i, rule.origin)
-            i += 1
 
             user_callback_name = rule.alias or rule.origin.name
             try:
@@ -243,16 +234,14 @@ class ParseTreeBuilder:
             except AttributeError:
                 f = partial(self.tree_class, user_callback_name)
 
-            self.user_aliases[rule] = rule.alias
-            rule.alias = internal_callback_name
-
             for w in wrapper_chain:
                 f = w(f)
 
-            if hasattr(callback, internal_callback_name):
+            if rule in callbacks:
                 raise GrammarError("Rule '%s' already exists" % (rule,))
-            setattr(callback, internal_callback_name, f)
 
-        return callback
+            callbacks[rule] = f
+
+        return callbacks
 
 ###}
diff --git a/lark/parser_frontends.py b/lark/parser_frontends.py
index af2a2fd..c351ddc 100644
--- a/lark/parser_frontends.py
+++ b/lark/parser_frontends.py
@@ -123,10 +123,7 @@ class CYK(WithLexer):
         self._analysis = GrammarAnalyzer(parser_conf)
         self._parser = cyk.Parser(parser_conf.rules, parser_conf.start)
 
-        self._postprocess = {}
-        for rule in parser_conf.rules:
-            a = rule.alias
-            self._postprocess[a] = a if callable(a) else (a and getattr(parser_conf.callback, a))
+        self.callbacks = parser_conf.callbacks
 
     def parse(self, text):
         tokens = list(self.lex(text))
@@ -142,11 +139,7 @@ class CYK(WithLexer):
         return self._apply_callback(tree)
 
     def _apply_callback(self, tree):
-        children = tree.children
-        callback = self._postprocess[tree.rule.alias]
-        assert callback, tree.rule.alias
-        r = callback(children)
-        return r
+        return self.callbacks[tree.rule](tree.children)
 
 
 def get_frontend(parser, lexer):
diff --git a/lark/parsers/cyk.py b/lark/parsers/cyk.py
index ee9ea8e..2121449 100644
--- a/lark/parsers/cyk.py
+++ b/lark/parsers/cyk.py
@@ -86,7 +86,7 @@ class Parser(object):
 
     def __init__(self, rules, start):
         super(Parser, self).__init__()
-        self.orig_rules = {rule.alias: rule for rule in rules}
+        self.orig_rules = {rule: rule for rule in rules}
         rules = [self._to_rule(rule) for rule in rules]
         self.grammar = to_cnf(Grammar(rules))
         self.start = NT(start)
@@ -98,7 +98,7 @@ class Parser(object):
         return Rule(
             lark_rule.origin, lark_rule.expansion,
             weight=lark_rule.options.priority if lark_rule.options and lark_rule.options.priority else 0,
-            alias=lark_rule.alias)
+            alias=lark_rule)
 
     def parse(self, tokenized):  # pylint: disable=invalid-name
         """Parses input, which is a list of tokens."""
diff --git a/lark/parsers/earley.py b/lark/parsers/earley.py
index 64e2a1d..0518174 100644
--- a/lark/parsers/earley.py
+++ b/lark/parsers/earley.py
@@ -27,7 +27,7 @@ class Parser:
 
         self.FIRST = analysis.FIRST
         self.NULLABLE = analysis.NULLABLE
-        self.callbacks = {}
+        self.callbacks = parser_conf.callbacks
         self.predictions = {}
 
         ## These could be moved to the grammar analyzer. Pre-computing these is *much* faster than
@@ -37,7 +37,6 @@ class Parser:
 
         self.forest_sum_visitor = None
         for rule in parser_conf.rules:
-            self.callbacks[rule] = rule.alias if callable(rule.alias) else getattr(parser_conf.callback, rule.alias)
             self.predictions[rule.origin] = [x.rule for x in analysis.expand_rule(rule.origin)]
 
             ## Detect if any rules have priorities set. If the user specified priority = "none" then
diff --git a/lark/parsers/earley_forest.py b/lark/parsers/earley_forest.py
index 8d9c148..89522cd 100644
--- a/lark/parsers/earley_forest.py
+++ b/lark/parsers/earley_forest.py
@@ -271,7 +271,8 @@ class ForestToTreeVisitor(ForestVisitor):
     according to some priority mechanism.
     """
     __slots__ = ['forest_sum_visitor', 'callbacks', 'output_stack']
-    def __init__(self, callbacks = None, forest_sum_visitor = None):
+    def __init__(self, callbacks, forest_sum_visitor = None):
+        assert callbacks
         self.forest_sum_visitor = forest_sum_visitor
         self.callbacks = callbacks
 
diff --git a/lark/parsers/lalr_parser.py b/lark/parsers/lalr_parser.py
index 6178c99..c30a92e 100644
--- a/lark/parsers/lalr_parser.py
+++ b/lark/parsers/lalr_parser.py
@@ -13,8 +13,7 @@ class Parser:
                    for r in parser_conf.rules), "LALR doesn't yet support prioritization"
         analysis = LALR_Analyzer(parser_conf, debug=debug)
         analysis.compute_lookahead()
-        callbacks = {rule: getattr(parser_conf.callback, rule.alias or rule.origin, None)
-                          for rule in parser_conf.rules}
+        callbacks = parser_conf.callbacks
 
         self._parse_table = analysis.parse_table
         self.parser_conf = parser_conf
diff --git a/lark/reconstruct.py b/lark/reconstruct.py
index 1fa6c7b..791eb85 100644
--- a/lark/reconstruct.py
+++ b/lark/reconstruct.py
@@ -112,7 +112,8 @@ class Reconstructor:
 
     def _reconstruct(self, tree):
         # TODO: ambiguity?
-        parser = earley.Parser(ParserConf(self.rules, None, tree.data), self._match, resolve_ambiguity=True)
+        callbacks = {rule: rule.alias for rule in self.rules}   # TODO pass callbacks through dict, instead of alias?
+        parser = earley.Parser(ParserConf(self.rules, callbacks, tree.data), self._match, resolve_ambiguity=True)
         unreduced_tree = parser.parse(tree.children)   # find a full derivation
         assert unreduced_tree.data == tree.data
         res = self.write_tokens.transform(unreduced_tree)
diff --git a/lark/tools/standalone.py b/lark/tools/standalone.py
index 99ee73c..3e6cc5d 100644
--- a/lark/tools/standalone.py
+++ b/lark/tools/standalone.py
@@ -186,8 +186,7 @@ class ParserAtoms:
         print('parse_table.end_state = %s' % self.parse_table.end_state)
         print('class Lark_StandAlone:')
         print('  def __init__(self, transformer=None, postlex=None):')
-        print('     callback = parse_tree_builder.create_callback(transformer=transformer)')
-        print('     callbacks = {rule: getattr(callback, rule.alias or rule.origin, None) for rule in RULES.values()}')
+        print('     callbacks = parse_tree_builder.create_callback(transformer=transformer)')
         print('     self.parser = _Parser(parse_table, callbacks)')
         print('     self.postlex = postlex')
         print('  def parse(self, stream):')
@@ -199,14 +198,13 @@ class ParserAtoms:
 class TreeBuilderAtoms:
     def __init__(self, lark):
         self.rules = lark.rules
-        self.ptb = lark._parse_tree_builder
 
     def print_python(self):
         # print('class InlineTransformer: pass')
         print('RULES = {')
         for i, r in enumerate(self.rules):
             rule_ids[r] = i
-            print('  %d: Rule(%r, [%s], alias=%r, options=%r),' % (i, r.origin, ', '.join(s.fullrepr for s in r.expansion), self.ptb.user_aliases[r], r.options ))
+            print('  %d: Rule(%r, [%s], alias=%r, options=%r),' % (i, r.origin, ', '.join(s.fullrepr for s in r.expansion), r.alias, r.options ))
         print('}')
         print('parse_tree_builder = ParseTreeBuilder(RULES.values(), Tree)')