diff --git a/scrapy/extensions/feedexport.py b/scrapy/extensions/feedexport.py
index d0430d0db..8029f85c9 100644
--- a/scrapy/extensions/feedexport.py
+++ b/scrapy/extensions/feedexport.py
@@ -306,12 +306,15 @@ class GCSFeedStorage(BlockingFeedStorage):
 
     def _store_in_thread(self, file: IO[bytes]) -> None:
         file.seek(0)
-        from google.cloud.storage import Client  # noqa: PLC0415
+        try:
+            from google.cloud.storage import Client  # noqa: PLC0415
 
-        client = Client(project=self.project_id)
-        bucket = client.get_bucket(self.bucket_name)
-        blob = bucket.blob(self.blob_name)
-        blob.upload_from_file(file, predefined_acl=self.acl)
+            client = Client(project=self.project_id)
+            bucket = client.get_bucket(self.bucket_name)
+            blob = bucket.blob(self.blob_name)
+            blob.upload_from_file(file, predefined_acl=self.acl)
+        finally:
+            file.close()
 
 
 class FTPFeedStorage(BlockingFeedStorage):
diff --git a/tests/test_feedexport_storages.py b/tests/test_feedexport_storages.py
index 5102f8e37..11e79775f 100644
--- a/tests/test_feedexport_storages.py
+++ b/tests/test_feedexport_storages.py
@@ -513,6 +513,34 @@ class TestGCSFeedStorage:
             client_mock.get_bucket.assert_called_once_with("mybucket")
             bucket_mock.blob.assert_called_once_with("export.csv")
             blob_mock.upload_from_file.assert_called_once_with(f, predefined_acl=acl)
+            f.close.assert_called_once_with()
+
+    @coroutine_test
+    async def test_store_closes_file_on_upload_error(self):
+        try:
+            from google.cloud.storage import Client  # noqa: F401,PLC0415
+        except ImportError:
+            pytest.skip("GCSFeedStorage requires google-cloud-storage")
+
+        uri = "gs://mybucket/export.csv"
+        project_id = "myproject-123"
+        acl = "publicRead"
+        (client_mock, bucket_mock, blob_mock) = mock_google_cloud_storage()
+        blob_mock.upload_from_file.side_effect = OSError("Upload failed")
+        with mock.patch("google.cloud.storage.Client") as m:
+            m.return_value = client_mock
+
+            f = mock.Mock()
+            storage = GCSFeedStorage(uri, project_id, acl)
+            with pytest.raises(OSError, match="Upload failed"):
+                await maybe_deferred_to_future(storage.store(f))
+
+            f.seek.assert_called_once_with(0)
+            m.assert_called_once_with(project=project_id)
+            client_mock.get_bucket.assert_called_once_with("mybucket")
+            bucket_mock.blob.assert_called_once_with("export.csv")
+            blob_mock.upload_from_file.assert_called_once_with(f, predefined_acl=acl)
+            f.close.assert_called_once_with()
 
     def test_overwrite_default(self):
         with LogCapture() as log: