diff --git a/src/transformers/models/auto/tokenization_auto.py b/src/transformers/models/auto/tokenization_auto.py
index 1b38f2e7a3f1..3d12426caa6f 100644
--- a/src/transformers/models/auto/tokenization_auto.py
+++ b/src/transformers/models/auto/tokenization_auto.py
@@ -358,7 +358,6 @@
     "internvl_chat",
     "jamba",
     "janus",
-    "kimi_k25",
     "llava",
     "llava_next",
     "minicpmv",
diff --git a/src/transformers/tokenization_utils_tokenizers.py b/src/transformers/tokenization_utils_tokenizers.py
index b516a777ecf1..fcd82078295e 100644
--- a/src/transformers/tokenization_utils_tokenizers.py
+++ b/src/transformers/tokenization_utils_tokenizers.py
@@ -1360,11 +1360,11 @@ def is_base_mistral(model_id: str) -> bool:
                         ),
                         behavior="isolated",
                     )
-                    current_pretokenizer = tokenizer.backend_tokenizer.pre_tokenizer
+                    current_pretokenizer = tokenizer.pre_tokenizer
                     # Check if it's already a Sequence
                     if isinstance(current_pretokenizer, tokenizers.pre_tokenizers.Sequence):
                         # Replace the first element (the Split pattern)
-                        tokenizer.backend_tokenizer.pre_tokenizer[0] = split_pretokenizer
+                        tokenizer.pre_tokenizer[0] = split_pretokenizer
                     else:
                         # Replace Metaspace with ByteLevel when adding Split, as Metaspace(split=False) doesn't
                         # work correctly with the Split pre-tokenizer and causes spaces to be lost during encoding
@@ -1374,7 +1374,7 @@ def is_base_mistral(model_id: str) -> bool:
                             )
 
                         # Not a Sequence, so create one with Split + current pretokenizer
-                        tokenizer.backend_tokenizer.pre_tokenizer = tokenizers.pre_tokenizers.Sequence(
+                        tokenizer.pre_tokenizer = tokenizers.pre_tokenizers.Sequence(
                             [
                                 split_pretokenizer,
                                 current_pretokenizer,