diff --git a/streaming/base/shared/prefix.py b/streaming/base/shared/prefix.py
index bff7dc067..a942b26ea 100644
--- a/streaming/base/shared/prefix.py
+++ b/streaming/base/shared/prefix.py
@@ -150,9 +150,10 @@ def _check_and_find(streams_local: list[str], streams_remote: list[Union[str, No
                             raise ValueError(
                                 f'Reused local directory: {streams_local} vs ' +
                                 f'{their_locals}. Provide a different one. If using ' +
-                                f'a unique local directory, try deleting the local directory and ' +
-                                f'call `streaming.base.util.clean_stale_shared_memory()` only once ' +
-                                f'in your script to clean up the stale shared memory before ' +
+                                f'a unique local directory, try deleting the local directory and '
+                                +
+                                f'call `streaming.base.util.clean_stale_shared_memory()` only once '
+                                + f'in your script to clean up the stale shared memory before ' +
                                 f'instantiation of `StreamingDataset`.')
     return prefix_int
 
@@ -208,10 +209,8 @@ def get_shm_prefix(streams_local: list[str],
     _check_self(streams_local)
 
     prefix_int = max([
-        _check_and_find_retrying(streams_local,
-                                 streams_remote,
-                                 shm_name=shm_name,
-                                 retry=retry) for shm_name in SHM_TO_CLEAN
+        _check_and_find_retrying(streams_local, streams_remote, shm_name=shm_name, retry=retry)
+        for shm_name in SHM_TO_CLEAN
     ])
 
     # First, the local leader registers the first available shm prefix, recording its locals.
@@ -235,6 +234,7 @@ def get_shm_prefix(streams_local: list[str],
                                f'local leader. This may be because you specified ' +
                                f'different ``local`` parameters from different ranks.')
 
+        their_locals, their_prefix_int = _unpack_locals(bytes(shm.buf))
         if streams_local != their_locals or prefix_int != their_prefix_int:
             raise RuntimeError(f'Internal error: shared memory registered does not match ' +
                                f'local leader as streams_local or prefix_int not match.')