diff --git a/gcloud/logging/_gax.py b/gcloud/logging/_gax.py
index fd8c3eff3e2b..bf368900b335 100644
--- a/gcloud/logging/_gax.py
+++ b/gcloud/logging/_gax.py
@@ -44,7 +44,7 @@ def __init__(self, gax_api):
         self._gax_api = gax_api
 
     def list_entries(self, projects, filter_='', order_by='',
-                     page_size=0, page_token=INITIAL_PAGE):
+                     page_size=0, page_token=None):
         """Return a page of log entry resources.
 
         :type projects: list of strings
@@ -73,6 +73,8 @@ def list_entries(self, projects, filter_='', order_by='',
                   if not None, indicates that more entries can be retrieved
                   with another call (pass that value as ``page_token``).
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         page_iter = self._gax_api.list_log_entries(
             projects, filter_, order_by, page_size, options)
@@ -135,7 +137,7 @@ class _SinksAPI(object):
     def __init__(self, gax_api):
         self._gax_api = gax_api
 
-    def list_sinks(self, project, page_size=0, page_token=INITIAL_PAGE):
+    def list_sinks(self, project, page_size=0, page_token=None):
         """List sinks for the project associated with this client.
 
         :type project: string
@@ -155,6 +157,8 @@ def list_sinks(self, project, page_size=0, page_token=INITIAL_PAGE):
                   if not None, indicates that more sinks can be retrieved
                   with another call (pass that value as ``page_token``).
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         path = 'projects/%s' % (project,)
         page_iter = self._gax_api.list_sinks(path, page_size, options)
@@ -279,7 +283,7 @@ class _MetricsAPI(object):
     def __init__(self, gax_api):
         self._gax_api = gax_api
 
-    def list_metrics(self, project, page_size=0, page_token=INITIAL_PAGE):
+    def list_metrics(self, project, page_size=0, page_token=None):
         """List metrics for the project associated with this client.
 
         :type project: string
@@ -299,6 +303,8 @@ def list_metrics(self, project, page_size=0, page_token=INITIAL_PAGE):
                   if not None, indicates that more metrics can be retrieved
                   with another call (pass that value as ``page_token``).
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         path = 'projects/%s' % (project,)
         page_iter = self._gax_api.list_log_metrics(path, page_size, options)
diff --git a/gcloud/pubsub/_gax.py b/gcloud/pubsub/_gax.py
index 4fde46a3f931..c0a10390ed40 100644
--- a/gcloud/pubsub/_gax.py
+++ b/gcloud/pubsub/_gax.py
@@ -36,7 +36,7 @@ class _PublisherAPI(object):
     def __init__(self, gax_api):
         self._gax_api = gax_api
 
-    def list_topics(self, project, page_size=0, page_token=INITIAL_PAGE):
+    def list_topics(self, project, page_size=0, page_token=None):
         """List topics for the project associated with this API.
 
         See:
@@ -60,6 +60,8 @@ def list_topics(self, project, page_size=0, page_token=INITIAL_PAGE):
                   more topics can be retrieved with another call (pass that
                   value as ``page_token``).
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         path = 'projects/%s' % (project,)
         page_iter = self._gax_api.list_topics(
@@ -162,7 +164,7 @@ def topic_publish(self, topic_path, messages):
         return result.message_ids
 
     def topic_list_subscriptions(self, topic_path, page_size=0,
-                                 page_token=INITIAL_PAGE):
+                                 page_token=None):
         """API call:  list subscriptions bound to a topic
 
         See:
@@ -187,6 +189,8 @@ def topic_list_subscriptions(self, topic_path, page_size=0,
         :raises: :exc:`gcloud.exceptions.NotFound` if the topic does not
                     exist
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         try:
             page_iter = self._gax_api.list_topic_subscriptions(
@@ -209,8 +213,7 @@ class _SubscriberAPI(object):
     def __init__(self, gax_api):
         self._gax_api = gax_api
 
-    def list_subscriptions(self, project, page_size=0,
-                           page_token=INITIAL_PAGE):
+    def list_subscriptions(self, project, page_size=0, page_token=None):
         """List subscriptions for the project associated with this API.
 
         See:
@@ -234,6 +237,8 @@ def list_subscriptions(self, project, page_size=0,
                   more topics can be retrieved with another call (pass that
                   value as ``page_token``).
         """
+        if page_token is None:
+            page_token = INITIAL_PAGE
         options = CallOptions(page_token=page_token)
         path = 'projects/%s' % (project,)
         page_iter = self._gax_api.list_subscriptions(