diff --git a/lark/common.py b/lark/common.py
index cc8c73c..714399a 100644
--- a/lark/common.py
+++ b/lark/common.py
@@ -17,9 +17,6 @@ class LexerConf(Serialize):
         self.skip_validation = skip_validation
         self.use_bytes = use_bytes
 
-    def _deserialize(self):
-        self.callbacks = {} # TODO
-
 ###}
 
 class ParserConf:
diff --git a/lark/lark.py b/lark/lark.py
index daab45b..8371943 100644
--- a/lark/lark.py
+++ b/lark/lark.py
@@ -11,7 +11,7 @@ from .common import LexerConf, ParserConf
 
 from .lexer import Lexer, TraditionalLexer, TerminalDef, UnexpectedToken
 from .parse_tree_builder import ParseTreeBuilder
-from .parser_frontends import get_frontend
+from .parser_frontends import get_frontend, _get_lexer_callbacks
 from .grammar import Rule
 
 import re
@@ -278,12 +278,10 @@ class Lark(Serialize):
                     rule.options.priority = None
 
         # TODO Deprecate lexer_callbacks?
-        lexer_callbacks = dict(self.options.lexer_callbacks)
-        if self.options.transformer:
-            t = self.options.transformer
-            for term in self.terminals:
-                if hasattr(t, term.name):
-                    lexer_callbacks[term.name] = getattr(t, term.name)
+        lexer_callbacks = (_get_lexer_callbacks(self.options.transformer, self.terminals)
+                           if self.options.transformer
+                           else {})
+        lexer_callbacks.update(self.options.lexer_callbacks)
 
         self.lexer_conf = LexerConf(self.terminals, re_module, self.ignore_tokens, self.options.postlex, lexer_callbacks, self.options.g_regex_flags, use_bytes=self.options.use_bytes)
 
@@ -344,7 +342,14 @@ class Lark(Serialize):
         self.rules = [Rule.deserialize(r, memo) for r in data['rules']]
         self.source = '<deserialized>'
         self._prepare_callbacks()
-        self.parser = self.parser_class.deserialize(data['parser'], memo, self._callbacks, self.options.postlex, re_module)
+        self.parser = self.parser_class.deserialize(
+            data['parser'],
+            memo,
+            self._callbacks,
+            self.options.postlex,
+            self.options.transformer,
+            re_module
+        )
         return self
 
     @classmethod
diff --git a/lark/parser_frontends.py b/lark/parser_frontends.py
index 33ad9bc..b993b9f 100644
--- a/lark/parser_frontends.py
+++ b/lark/parser_frontends.py
@@ -1,6 +1,6 @@
 from .utils import get_regexp_width, Serialize
 from .parsers.grammar_analysis import GrammarAnalyzer
-from .lexer import TraditionalLexer, ContextualLexer, Lexer, Token
+from .lexer import TraditionalLexer, ContextualLexer, Lexer, Token, TerminalDef
 from .parsers import earley, xearley, cyk
 from .parsers.lalr_parser import LALR_Parser
 from .grammar import Rule
@@ -58,6 +58,15 @@ class _ParserFrontend(Serialize):
         return self.parser.parse(input, start, *args)
 
 
+def _get_lexer_callbacks(transformer, terminals):
+    result = {}
+    for terminal in terminals:
+        callback = getattr(transformer, terminal.name, None)
+        if callback is not None:
+            result[terminal.name] = callback
+    return result
+
+
 class WithLexer(_ParserFrontend):
     lexer = None
     parser = None
@@ -73,13 +82,18 @@ class WithLexer(_ParserFrontend):
         self.postlex = lexer_conf.postlex
 
     @classmethod
-    def deserialize(cls, data, memo, callbacks, postlex, re_module):
+    def deserialize(cls, data, memo, callbacks, postlex, transformer, re_module):
         inst = super(WithLexer, cls).deserialize(data, memo)
+
         inst.postlex = postlex
         inst.parser = LALR_Parser.deserialize(inst.parser, memo, callbacks)
+
+        terminals = [item for item in memo.values() if isinstance(item, TerminalDef)]
+        inst.lexer_conf.callbacks = _get_lexer_callbacks(transformer, terminals)
         inst.lexer_conf.re_module = re_module
         inst.lexer_conf.skip_validation=True
         inst.init_lexer()
+
         return inst
 
     def _serialize(self, data, memo):
@@ -229,4 +243,3 @@ class CYK(WithLexer):
 
     def _apply_callback(self, tree):
         return self.callbacks[tree.rule](tree.children)
-
diff --git a/tests/test_tools.py b/tests/test_tools.py
index 1e0d78e..e691237 100644
--- a/tests/test_tools.py
+++ b/tests/test_tools.py
@@ -106,6 +106,33 @@ class TestStandalone(TestCase):
         x = l.parse('(\n)\n')
         self.assertEqual(x, Tree('start', []))
 
+    def test_transformer(self):
+        grammar = r"""
+            start: some_rule "(" SOME_TERMINAL ")"
+            some_rule: SOME_TERMINAL
+            SOME_TERMINAL: /[A-Za-z_][A-Za-z0-9_]*/
+        """
+        context = self._create_standalone(grammar)
+        _Lark = context["Lark_StandAlone"]
+
+        _Token = context["Token"]
+        _Tree = context["Tree"]
+
+        class MyTransformer(context["Transformer"]):
+            def SOME_TERMINAL(self, token):
+                return _Token("SOME_TERMINAL", "token is transformed")
+
+            def some_rule(self, children):
+                return _Tree("rule_is_transformed", [])
+
+        parser = _Lark(transformer=MyTransformer())
+        self.assertEqual(
+            parser.parse("FOO(BAR)"),
+            _Tree("start", [
+                _Tree("rule_is_transformed", []),
+                _Token("SOME_TERMINAL", "token is transformed")
+            ])
+        )
 
 
 if __name__ == '__main__':