diff --git a/airbyte-cdk/python/airbyte_cdk/sources/declarative/models/declarative_component_schema.py b/airbyte-cdk/python/airbyte_cdk/sources/declarative/models/declarative_component_schema.py
index 1e996c2f8d8a..1b1e0220a1f1 100644
--- a/airbyte-cdk/python/airbyte_cdk/sources/declarative/models/declarative_component_schema.py
+++ b/airbyte-cdk/python/airbyte_cdk/sources/declarative/models/declarative_component_schema.py
@@ -1440,7 +1440,7 @@ class SessionTokenAuthenticator(BaseModel):
         description='Authentication method to use for requests sent to the API, specifying how to inject the session token.',
         title='Data Request Authentication',
     )
-    decoder: Optional[Union[JsonDecoder, JsonlDecoder, IterableDecoder]] = Field(
+    decoder: Optional[JsonDecoder] = Field(
         None, description='Component decoding the response', title='Decoder'
     )
     parameters: Optional[Dict[str, Any]] = Field(None, alias='$parameters')
diff --git a/airbyte-cdk/python/airbyte_cdk/sources/declarative/parsers/model_to_component_factory.py b/airbyte-cdk/python/airbyte_cdk/sources/declarative/parsers/model_to_component_factory.py
index 7742e03a5e0b..3dc9c48e7701 100644
--- a/airbyte-cdk/python/airbyte_cdk/sources/declarative/parsers/model_to_component_factory.py
+++ b/airbyte-cdk/python/airbyte_cdk/sources/declarative/parsers/model_to_component_factory.py
@@ -381,9 +381,9 @@ def create_legacy_to_per_partition_state_migration(
     def create_session_token_authenticator(
         self, model: SessionTokenAuthenticatorModel, config: Config, name: str, **kwargs: Any
     ) -> Union[ApiKeyAuthenticator, BearerAuthenticator]:
-        if not isinstance(model.decoder, JsonDecoder):
-            raise ValueError(f"Provided decoder of {type(model.decoder)=} is not supported. Please set JsonDecoder instead.")
         decoder = self._create_component_from_model(model=model.decoder, config=config) if model.decoder else JsonDecoder(parameters={})
+        if not isinstance(decoder, JsonDecoder):
+            raise ValueError(f"Provided decoder of {type(model.decoder)=} is not supported. Please set JsonDecoder instead.")
         login_requester = self._create_component_from_model(
             model=model.login_requester, config=config, name=f"{name}_login_requester", decoder=decoder
         )