diff --git a/src/transformers/adapters/wrappers/configuration.py b/src/transformers/adapters/wrappers/configuration.py
index 47656a667..3ffb3f22d 100644
--- a/src/transformers/adapters/wrappers/configuration.py
+++ b/src/transformers/adapters/wrappers/configuration.py
@@ -1,5 +1,3 @@
-import types
-
 from ...configuration_utils import PretrainedConfig
 from ...models.encoder_decoder.configuration_encoder_decoder import EncoderDecoderConfig
 from ..configuration import ModelAdaptersConfig
@@ -40,21 +38,6 @@
 }
 
 
-def _to_dict_new(self):
-    output = self._to_dict_original()
-    if hasattr(self, "adapters") and not isinstance(output["adapters"], dict):
-        output["adapters"] = self.adapters.to_dict()
-    if "custom_heads" in output.keys():
-        del output["custom_heads"]
-
-    # delete handles to overriden methods
-    del output["to_dict"]
-    del output["_to_dict_original"]
-    del output["is_adaptable"]
-
-    return output
-
-
 def wrap_config(config: PretrainedConfig) -> PretrainedConfig:
     """
     Makes required changes to a model config class to allow usage with adapters.
@@ -86,11 +69,6 @@ def wrap_config(config: PretrainedConfig) -> PretrainedConfig:
             if key not in config.attribute_map:
                 config.attribute_map[key] = value
 
-    # Override to_dict() to add adapters
-    if not hasattr(config, "_to_dict_original"):
-        config._to_dict_original = config.to_dict
-        config.to_dict = types.MethodType(_to_dict_new, config)
-
     # Ensure custom_heads attribute is present
     if not hasattr(config, "custom_heads"):
         config.custom_heads = {}
diff --git a/src/transformers/configuration_utils.py b/src/transformers/configuration_utils.py
index f66b5734b..2073363cc 100755
--- a/src/transformers/configuration_utils.py
+++ b/src/transformers/configuration_utils.py
@@ -771,6 +771,16 @@ def to_diff_dict(self) -> Dict[str, Any]:
 
         return serializable_config_dict
 
+    def adapters_to_dict(self, output):
+        # Adapter-specific changes
+        if hasattr(self, "adapters") and not isinstance(output["adapters"], dict):
+            output["adapters"] = self.adapters.to_dict()
+        if "custom_heads" in output:
+            del output["custom_heads"]
+        if "is_adaptable" in output:
+            del output["is_adaptable"]
+        return output
+
     def to_dict(self) -> Dict[str, Any]:
         """
         Serializes this instance to a Python dictionary.
@@ -789,6 +799,8 @@ def to_dict(self) -> Dict[str, Any]:
 
         self.dict_torch_dtype_to_str(output)
 
+        self.adapters_to_dict(output)
+
         return output
 
     def to_json_string(self, use_diff: bool = True) -> str:
diff --git a/src/transformers/models/encoder_decoder/configuration_encoder_decoder.py b/src/transformers/models/encoder_decoder/configuration_encoder_decoder.py
index 1fca8a10f..5d562a61d 100644
--- a/src/transformers/models/encoder_decoder/configuration_encoder_decoder.py
+++ b/src/transformers/models/encoder_decoder/configuration_encoder_decoder.py
@@ -116,4 +116,7 @@ def to_dict(self):
         output["encoder"] = self.encoder.to_dict()
         output["decoder"] = self.decoder.to_dict()
         output["model_type"] = self.__class__.model_type
+
+        self.adapters_to_dict(output)
+
         return output