diff --git a/pubsub/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py b/api_core/google/api_core/bidi.py
similarity index 100%
rename from pubsub/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py
rename to api_core/google/api_core/bidi.py
diff --git a/pubsub/tests/unit/pubsub_v1/subscriber/test_bidi.py b/api_core/tests/unit/test_bidi.py
similarity index 99%
rename from pubsub/tests/unit/pubsub_v1/subscriber/test_bidi.py
rename to api_core/tests/unit/test_bidi.py
index 058cd53c29cf..a37770612de8 100644
--- a/pubsub/tests/unit/pubsub_v1/subscriber/test_bidi.py
+++ b/api_core/tests/unit/test_bidi.py
@@ -21,7 +21,7 @@
 from six.moves import queue
 
 from google.api_core import exceptions
-from google.cloud.pubsub_v1.subscriber._protocol import bidi
+from google.api_core import bidi
 
 
 class Test_RequestQueueGenerator(object):
diff --git a/pubsub/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py b/pubsub/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
index 17d1a2cad166..fdc868b4fa3a 100644
--- a/pubsub/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
+++ b/pubsub/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py
@@ -22,9 +22,9 @@
 import grpc
 import six
 
+from google.api_core import bidi
 from google.api_core import exceptions
 from google.cloud.pubsub_v1 import types
-from google.cloud.pubsub_v1.subscriber._protocol import bidi
 from google.cloud.pubsub_v1.subscriber._protocol import dispatcher
 from google.cloud.pubsub_v1.subscriber._protocol import heartbeater
 from google.cloud.pubsub_v1.subscriber._protocol import histogram
diff --git a/pubsub/tests/unit/pubsub_v1/subscriber/test_streaming_pull_manager.py b/pubsub/tests/unit/pubsub_v1/subscriber/test_streaming_pull_manager.py
index 15f3bc95db80..4acbf74ea8c0 100644
--- a/pubsub/tests/unit/pubsub_v1/subscriber/test_streaming_pull_manager.py
+++ b/pubsub/tests/unit/pubsub_v1/subscriber/test_streaming_pull_manager.py
@@ -17,13 +17,13 @@
 import mock
 import pytest
 
+from google.api_core import bidi
 from google.api_core import exceptions
 from google.cloud.pubsub_v1 import types
 from google.cloud.pubsub_v1.gapic import subscriber_client_config
 from google.cloud.pubsub_v1.subscriber import client
 from google.cloud.pubsub_v1.subscriber import message
 from google.cloud.pubsub_v1.subscriber import scheduler
-from google.cloud.pubsub_v1.subscriber._protocol import bidi
 from google.cloud.pubsub_v1.subscriber._protocol import dispatcher
 from google.cloud.pubsub_v1.subscriber._protocol import heartbeater
 from google.cloud.pubsub_v1.subscriber._protocol import leaser