diff --git a/docs/source/custom_models.mdx b/docs/source/custom_models.mdx
index b7205241bab5..a83c90b20df3 100644
--- a/docs/source/custom_models.mdx
+++ b/docs/source/custom_models.mdx
@@ -213,6 +213,12 @@ code of the model is saved.
 
 ## Sending the code to the Hub
 
+<Tip warning={true}>
+
+This API is experimental and may have some slight breaking changes in the next releases.
+
+</Tip>
+
 First, make sure your model is fully defined in a `.py` file. It can rely on relative imports to some other files as
 long as all the files are in the same directory (we don't support submodules for this feature yet). For our example,
 we'll define a `modeling_resnet.py` file and a `configuration_resnet.py` file in a folder of the current working
diff --git a/src/transformers/configuration_utils.py b/src/transformers/configuration_utils.py
index 3a43677a7042..580de6b91ee5 100755
--- a/src/transformers/configuration_utils.py
+++ b/src/transformers/configuration_utils.py
@@ -867,6 +867,12 @@ def register_for_auto_class(cls, auto_class="AutoConfig"):
         Register this class with a given auto class. This should only be used for custom configurations as the ones in
         the library are already mapped with `AutoConfig`.
 
+        <Tip warning={true}>
+
+        This API is experimental and may have some slight breaking changes in the next releases.
+
+        </Tip>
+
         Args:
             auto_class (`str` or `type`, *optional*, defaults to `"AutoConfig"`):
                 The auto class to register this new configuration with.
diff --git a/src/transformers/modeling_flax_utils.py b/src/transformers/modeling_flax_utils.py
index 3afc82e97e5c..969fd6daf22c 100644
--- a/src/transformers/modeling_flax_utils.py
+++ b/src/transformers/modeling_flax_utils.py
@@ -725,6 +725,12 @@ def register_for_auto_class(cls, auto_class="FlaxAutoModel"):
         Register this class with a given auto class. This should only be used for custom models as the ones in the
         library are already mapped with an auto class.
 
+        <Tip warning={true}>
+
+        This API is experimental and may have some slight breaking changes in the next releases.
+
+        </Tip>
+
         Args:
             auto_class (`str` or `type`, *optional*, defaults to `"FlaxAutoModel"`):
                 The auto class to register this new model with.
diff --git a/src/transformers/modeling_tf_utils.py b/src/transformers/modeling_tf_utils.py
index 54f465215fb2..5e37a1818df8 100644
--- a/src/transformers/modeling_tf_utils.py
+++ b/src/transformers/modeling_tf_utils.py
@@ -2021,6 +2021,12 @@ def register_for_auto_class(cls, auto_class="TFAutoModel"):
         Register this class with a given auto class. This should only be used for custom models as the ones in the
         library are already mapped with an auto class.
 
+        <Tip warning={true}>
+
+        This API is experimental and may have some slight breaking changes in the next releases.
+
+        </Tip>
+
         Args:
             auto_class (`str` or `type`, *optional*, defaults to `"TFAutoModel"`):
                 The auto class to register this new model with.
diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index e431c5a334a4..bc93e0616bb4 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -1821,6 +1821,12 @@ def register_for_auto_class(cls, auto_class="AutoModel"):
         Register this class with a given auto class. This should only be used for custom models as the ones in the
         library are already mapped with an auto class.
 
+        <Tip warning={true}>
+
+        This API is experimental and may have some slight breaking changes in the next releases.
+
+        </Tip>
+
         Args:
             auto_class (`str` or `type`, *optional*, defaults to `"AutoModel"`):
                 The auto class to register this new model with.
diff --git a/src/transformers/tokenization_utils_base.py b/src/transformers/tokenization_utils_base.py
index e60d4331edae..27ed8b8984a7 100644
--- a/src/transformers/tokenization_utils_base.py
+++ b/src/transformers/tokenization_utils_base.py
@@ -3417,6 +3417,12 @@ def register_for_auto_class(cls, auto_class="AutoTokenizer"):
         Register this class with a given auto class. This should only be used for custom tokenizers as the ones in the
         library are already mapped with `AutoTokenizer`.
 
+        <Tip warning={true}>
+
+        This API is experimental and may have some slight breaking changes in the next releases.
+
+        </Tip>
+
         Args:
             auto_class (`str` or `type`, *optional*, defaults to `"AutoTokenizer"`):
                 The auto class to register this new tokenizer with.