diff --git a/tokenizer_config.json b/tokenizer_config.json
index a6000a7..0431558 100644
--- a/tokenizer_config.json
+++ b/tokenizer_config.json
@@ -38,6 +38,6 @@
   "bos_token": "<|endoftext|>",
   "clean_up_tokenization_spaces": true,
   "eos_token": "<|endoftext|>",
-  "tokenizer_class": "GPT2Tokenizer",
+  "tokenizer_class": "GPT2TokenizerFast",
   "unk_token": "<|endoftext|>"
 }
\ No newline at end of file