diff --git a/airbyte-integrations/connectors/source-zendesk-support/source_zendesk_support/source.py b/airbyte-integrations/connectors/source-zendesk-support/source_zendesk_support/source.py
index 9b744703febe..3c551a039c4e 100644
--- a/airbyte-integrations/connectors/source-zendesk-support/source_zendesk_support/source.py
+++ b/airbyte-integrations/connectors/source-zendesk-support/source_zendesk_support/source.py
@@ -44,9 +44,11 @@ def __init__(self, email: str, password: str):
 
 class SourceZendeskSupport(YamlDeclarativeSource):
     def __init__(self, catalog: Optional[ConfiguredAirbyteCatalog], config: Optional[Mapping[str, Any]], state: TState, **kwargs):
-        if config and not config.get("start_date", None):
-            config["start_date"] = SourceZendeskSupport.get_default_start_date()
-        super().__init__(catalog=catalog, config=config, state=state, **{"path_to_yaml": "manifest.yaml"})
+        # Before 2024-11-11, the config was being modified in `streams`. We can't do that anymore because `ConcurrentDeclarativeSource` use
+        # the config to make concurrent components. Hence, the "main" config needs to be the declarative one and if Python sources need
+        # something a bit different, it needs to deduce it from the declarative config
+        declarative_config = SourceZendeskSupport.convert_config_to_declarative_stream_args(config) if config else None
+        super().__init__(catalog=catalog, config=declarative_config, state=state, **{"path_to_yaml": "manifest.yaml"})
 
     @classmethod
     def get_default_start_date(cls) -> str:
@@ -112,13 +114,12 @@ def convert_config2stream_args(cls, config: Mapping[str, Any]) -> Mapping[str, A
 
     @classmethod
     def convert_config_to_declarative_stream_args(cls, config: Mapping[str, Any]) -> Mapping[str, Any]:
-        """Convert input configs to parameters of the future streams
-        This function is used by unit tests too
+        """
+        Sets defaults to `start_date` and `ignore_pagination`.
         """
         return {
             "subdomain": config["subdomain"],
             "start_date": config.get("start_date", cls.get_default_start_date()),
-            "auth_type": config.get("auth_type"),
             "credentials": config.get("credentials"),
             "ignore_pagination": config.get("ignore_pagination", False),
         }
@@ -169,8 +170,7 @@ def check_enterprise_streams(self, declarative_streams: List[Stream]) -> List[St
         return all_streams
 
     def streams(self, config: Mapping[str, Any]) -> List[Stream]:
-        args = self.convert_config_to_declarative_stream_args(config)
-        declarative_streams = super().streams(args)
+        declarative_streams = super().streams(config)
 
         nested_streams = self.get_nested_streams(config)
         declarative_streams.extend(nested_streams)