diff --git a/src/allmydata/immutable/offloaded.py b/src/allmydata/immutable/offloaded.py
index d574b980d..4e18ad216 100644
--- a/src/allmydata/immutable/offloaded.py
+++ b/src/allmydata/immutable/offloaded.py
@@ -141,7 +141,7 @@ class CHKCheckerAndUEBFetcher(object):
 
 
 @implementer(interfaces.RICHKUploadHelper)
-class CHKUploadHelper(Referenceable, upload.CHKUploader):
+class CHKUploadHelper(Referenceable, upload.CHKUploader):  # type: ignore # warner/foolscap#78
     """I am the helper-server -side counterpart to AssistedUploader. I handle
     peer selection, encoding, and share pushing. I read ciphertext from the
     remote AssistedUploader.
@@ -502,7 +502,7 @@ class LocalCiphertextReader(AskUntilSuccessMixin):
 
 
 @implementer(interfaces.RIHelper, interfaces.IStatsProducer)
-class Helper(Referenceable):
+class Helper(Referenceable):  # type: ignore # warner/foolscap#78
     """
     :ivar dict[bytes, CHKUploadHelper] _active_uploads: For any uploads which
         have been started but not finished, a mapping from storage index to the
diff --git a/src/allmydata/immutable/upload.py b/src/allmydata/immutable/upload.py
index e77cbb30b..18f818504 100644
--- a/src/allmydata/immutable/upload.py
+++ b/src/allmydata/immutable/upload.py
@@ -1423,7 +1423,7 @@ class LiteralUploader(object):
         return self._status
 
 @implementer(RIEncryptedUploadable)
-class RemoteEncryptedUploadable(Referenceable):
+class RemoteEncryptedUploadable(Referenceable):  # type: ignore # warner/foolscap#78
 
     def __init__(self, encrypted_uploadable, upload_status):
         self._eu = IEncryptedUploadable(encrypted_uploadable)
diff --git a/src/allmydata/storage/immutable.py b/src/allmydata/storage/immutable.py
index 778c0ddf8..4b60d79f1 100644
--- a/src/allmydata/storage/immutable.py
+++ b/src/allmydata/storage/immutable.py
@@ -202,7 +202,7 @@ class ShareFile(object):
 
 
 @implementer(RIBucketWriter)
-class BucketWriter(Referenceable):
+class BucketWriter(Referenceable):  # type: ignore # warner/foolscap#78
 
     def __init__(self, ss, incominghome, finalhome, max_size, lease_info, canary):
         self.ss = ss
@@ -301,7 +301,7 @@ class BucketWriter(Referenceable):
 
 
 @implementer(RIBucketReader)
-class BucketReader(Referenceable):
+class BucketReader(Referenceable):  # type: ignore # warner/foolscap#78
 
     def __init__(self, ss, sharefname, storage_index=None, shnum=None):
         self.ss = ss