diff --git a/doc/source/conf.py b/doc/source/conf.py
index 6e89f69..2597f04 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -140,9 +140,8 @@
 git_cmd = ["git", "log", "--pretty=format:'%ad, commit %h'", "--date=local",
    "-n1"]
 try:
-    html_last_updated_fmt = subprocess.Popen(git_cmd,
-                                             stdout=subprocess.PIPE).\
-                                             communicate()[0]
+    html_last_updated_fmt = str(
+        subprocess.Popen(git_cmd, stdout=subprocess.PIPE).communicate()[0])
 except Exception:
     warnings.warn('Cannot get last updated time from git repository. '
                   'Not setting "html_last_updated_fmt".')
@@ -183,3 +182,6 @@
 
 # This is the file name suffix for HTML files (e.g. ".xhtml").
 #html_file_suffix = None
+
+# A list of warning types to suppress arbitrary warning messages.
+suppress_warnings = ['image.nonlocal_uri']
diff --git a/setup.cfg b/setup.cfg
index 96313fd..b2035bc 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -45,12 +45,10 @@
     tempest.config = tempest.config:list_opts
 
 [build_sphinx]
-all_files = 1
+all-files = 1
+warning-is-error = 1
 build-dir = doc/build
 source-dir = doc/source
 
-[pbr]
-warnerrors = True
-
 [wheel]
 universal = 1
diff --git a/tempest/test_discover/plugins.py b/tempest/test_discover/plugins.py
index 276cf3c..613ab92 100644
--- a/tempest/test_discover/plugins.py
+++ b/tempest/test_discover/plugins.py
@@ -102,11 +102,10 @@
         in any ServiceClients object instantiated by tests.
         The default implementation returns an empty list.
 
-        :return list of dictionaries. Each element of the list represents
-            the service client for an API. Each dict must define all
-            parameters required for the invocation of
-            `service_clients.ServiceClients.register_service_client_module`.
-        :rtype: list
+        :returns: Each element of the list represents the service client for an
+          API. Each dict must define all parameters required for the invocation
+          of `service_clients.ServiceClients.register_service_client_module`.
+        :rtype: list of dictionaries
 
         Example: