diff --git a/unsloth/tokenizer_utils.py b/unsloth/tokenizer_utils.py
index 1cad00d44d..4b9fd5e133 100644
--- a/unsloth/tokenizer_utils.py
+++ b/unsloth/tokenizer_utils.py
@@ -915,7 +915,7 @@ def patch_sft_trainer_tokenizer():
         check_text = \
         "\n"\
         "if 'tokenizer' not in locals(): tokenizer = processing_class\n"\
-        "test_text = dataset[0][dataset_text_field] if (formatting_func is not None and dataset_text_field is None) else formatting_func(dataset[0])[0]\n"\
+        "test_text = dataset[0][dataset_text_field] if (formatting_func is None and dataset_text_field is not None) else formatting_func(dataset[0])[0]\n"\
         "chat_template = getattr(tokenizer, 'chat_template', None)\n"\
         "chat_template = '' if chat_template is None else chat_template\n"\
         "has_bos_token_already = (test_text.startswith(tokenizer.bos_token) or tokenizer.bos_token in chat_template) "\