diff --git a/stac_fastapi/pgstac/app.py b/stac_fastapi/pgstac/app.py
index 45f5a9c..2c8d79b 100644
--- a/stac_fastapi/pgstac/app.py
+++ b/stac_fastapi/pgstac/app.py
@@ -17,16 +17,13 @@
     create_request_model,
 )
 from stac_fastapi.extensions.core import (
-    CollectionSearchExtension,
     FieldsExtension,
     FilterExtension,
     SortExtension,
     TokenPaginationExtension,
     TransactionExtension,
 )
-from stac_fastapi.extensions.core.collection_search.request import (
-    BaseCollectionSearchGetRequest,
-)
+from stac_fastapi.extensions.core.collection_search import CollectionSearchExtension
 from stac_fastapi.extensions.third_party import BulkTransactionExtension
 
 from stac_fastapi.pgstac.config import Settings
@@ -52,10 +49,6 @@
     "bulk_transactions": BulkTransactionExtension(client=BulkTransactionsClient()),
 }
 
-collections_extensions_map = {
-    "collection_search": CollectionSearchExtension(),
-}
-
 if enabled_extensions := os.getenv("ENABLED_EXTENSIONS"):
     _enabled_extensions = enabled_extensions.split(",")
     extensions = [
@@ -63,14 +56,9 @@
         for key, extension in extensions_map.items()
         if key in _enabled_extensions
     ]
-    collection_extensions = [
-        extension
-        for key, extension in collections_extensions_map.items()
-        if key in _enabled_extensions
-    ]
 else:
+    _enabled_extensions = list(extensions_map.keys()) + ["collection_search"]
     extensions = list(extensions_map.values())
-    collection_extensions = list(collections_extensions_map.values())
 
 
 if any(isinstance(ext, TokenPaginationExtension) for ext in extensions):
@@ -83,13 +71,10 @@
 else:
     items_get_request_model = ItemCollectionUri
 
-if any(isinstance(ext, CollectionSearchExtension) for ext in collection_extensions):
-    collections_get_request_model = create_request_model(
-        model_name="CollectionsGetRequest",
-        base_model=BaseCollectionSearchGetRequest,
-        extensions=extensions,
-        request_type="GET",
-    )
+if "collection_search" in _enabled_extensions:
+    collection_extension = CollectionSearchExtension()
+    collections_get_request_model = collection_extension.GET
+    extensions.append(collection_extension)
 else:
     collections_get_request_model = EmptyRequest
 
@@ -98,7 +83,7 @@
 
 api = StacApi(
     settings=settings,
-    extensions=extensions + collection_extensions,
+    extensions=extensions,
     client=CoreCrudClient(post_request_model=post_request_model),  # type: ignore
     response_class=ORJSONResponse,
     items_get_request_model=items_get_request_model,