diff --git a/special_tokens_map.json b/special_tokens_map.json
index 6dc4d43..271881d 100644
--- a/special_tokens_map.json
+++ b/special_tokens_map.json
@@ -1 +1 @@
-{"eos_token": "</s>", "unk_token": "<unk>", "pad_token": "<pad>"}
\ No newline at end of file
+{"eos_token": "</s>", "unk_token": "<unk>", "pad_token": "<pad>", "mask_token": "<mask_2>"}
\ No newline at end of file