diff --git a/lib/ansible/modules/monitoring/grafana_dashboard.py b/lib/ansible/modules/monitoring/grafana_dashboard.py
index e351204693c..74cf592dbad 100644
--- a/lib/ansible/modules/monitoring/grafana_dashboard.py
+++ b/lib/ansible/modules/monitoring/grafana_dashboard.py
@@ -107,11 +107,12 @@ slug:
   sample: foo
 '''
 
-import base64
 import json
-import os
+import base64
+
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.urls import fetch_url
+from ansible.module_utils._text import to_bytes
 
 __metaclass__ = type
 
@@ -166,7 +167,7 @@ def grafana_create_dashboard(module, data):
     if 'grafana_api_key' in data and data['grafana_api_key']:
         headers['Authorization'] = "Bearer %s" % data['grafana_api_key']
     else:
-        auth = base64.encodestring('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', '')
+        auth = base64.b64encode(to_bytes('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', ''))
         headers['Authorization'] = 'Basic %s' % auth
         grafana_switch_organisation(module, data['grafana_url'], data['org_id'], headers)
 
@@ -224,7 +225,7 @@ def grafana_delete_dashboard(module, data):
     if 'grafana_api_key' in data and data['grafana_api_key']:
         headers['Authorization'] = "Bearer %s" % data['grafana_api_key']
     else:
-        auth = base64.encodestring('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', '')
+        auth = base64.b64encode(to_bytes('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', ''))
         headers['Authorization'] = 'Basic %s' % auth
         grafana_switch_organisation(module, data['grafana_url'], data['org_id'], headers)
 
@@ -257,7 +258,7 @@ def grafana_export_dashboard(module, data):
     if 'grafana_api_key' in data and data['grafana_api_key']:
         headers['Authorization'] = "Bearer %s" % data['grafana_api_key']
     else:
-        auth = base64.encodestring('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', '')
+        auth = base64.b64encode(to_bytes('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', ''))
         headers['Authorization'] = 'Basic %s' % auth
         grafana_switch_organisation(module, data['grafana_url'], data['org_id'], headers)
 
diff --git a/lib/ansible/modules/monitoring/grafana_datasource.py b/lib/ansible/modules/monitoring/grafana_datasource.py
index 3e8acde8576..e5f1f59bcf2 100644
--- a/lib/ansible/modules/monitoring/grafana_datasource.py
+++ b/lib/ansible/modules/monitoring/grafana_datasource.py
@@ -243,11 +243,12 @@ after:
         "withCredentials": false }
 '''
 
-import base64
 import json
-import os
+import base64
+
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.urls import fetch_url
+from ansible.module_utils._text import to_bytes
 
 __metaclass__ = type
 
@@ -349,7 +350,7 @@ def grafana_create_datasource(module, data):
     if 'grafana_api_key' in data and data['grafana_api_key'] is not None:
         headers['Authorization'] = "Bearer %s" % data['grafana_api_key']
     else:
-        auth = base64.encodestring('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', '')
+        auth = base64.b64encode(to_bytes('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', ''))
         headers['Authorization'] = 'Basic %s' % auth
         grafana_switch_organisation(module, data['grafana_url'], data['org_id'], headers)
 
@@ -409,7 +410,7 @@ def grafana_delete_datasource(module, data):
     if 'grafana_api_key' in data and data['grafana_api_key']:
         headers['Authorization'] = "Bearer %s" % data['grafana_api_key']
     else:
-        auth = base64.encodestring('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', '')
+        auth = base64.b64encode(to_bytes('%s:%s' % (data['grafana_user'], data['grafana_password'])).replace('\n', ''))
         headers['Authorization'] = 'Basic %s' % auth
         grafana_switch_organisation(module, data['grafana_url'], data['org_id'], headers)
 
diff --git a/lib/ansible/modules/monitoring/pagerduty.py b/lib/ansible/modules/monitoring/pagerduty.py
index 7d9f57af034..14c15d76ae1 100644
--- a/lib/ansible/modules/monitoring/pagerduty.py
+++ b/lib/ansible/modules/monitoring/pagerduty.py
@@ -164,19 +164,20 @@ EXAMPLES = '''
     service: '{{ pd_window.result.maintenance_window.id }}'
 '''
 
-import base64
 import datetime
 import json
+import base64
 
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.urls import fetch_url
+from ansible.module_utils._text import to_bytes
 
 
 def auth_header(user, passwd, token):
     if token:
         return "Token token=%s" % token
 
-    auth = base64.encodestring('%s:%s' % (user, passwd)).replace('\n', '')
+    auth = base64.b64encode(to_bytes('%s:%s' % (user, passwd)).replace('\n', ''))
     return "Basic %s" % auth
 
 
diff --git a/lib/ansible/modules/network/citrix/_netscaler.py b/lib/ansible/modules/network/citrix/_netscaler.py
index b8bf36bf347..e5347ce51af 100644
--- a/lib/ansible/modules/network/citrix/_netscaler.py
+++ b/lib/ansible/modules/network/citrix/_netscaler.py
@@ -88,14 +88,14 @@ EXAMPLES = '''
     action: disable
 '''
 
-import base64
 import json
 import socket
 import traceback
+import base64
 
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.six.moves.urllib.parse import urlencode
-from ansible.module_utils._text import to_native
+from ansible.module_utils._text import to_native, to_bytes
 from ansible.module_utils.urls import fetch_url
 
 
@@ -115,7 +115,7 @@ class netscaler(object):
         if not len(data_json):
             data_json = None
 
-        auth = base64.encodestring('%s:%s' % (self._nsc_user, self._nsc_pass)).replace('\n', '').strip()
+        auth = base64.b64encode(to_bytes('%s:%s' % (self._nsc_user, self._nsc_pass)).replace('\n', '').strip())
         headers = {
             'Authorization': 'Basic %s' % auth,
             'Content-Type': 'application/x-www-form-urlencoded',
diff --git a/lib/ansible/modules/source_control/github_hooks.py b/lib/ansible/modules/source_control/github_hooks.py
index ef5c19be1ab..e1480f668e1 100644
--- a/lib/ansible/modules/source_control/github_hooks.py
+++ b/lib/ansible/modules/source_control/github_hooks.py
@@ -80,15 +80,16 @@ EXAMPLES = '''
   delegate_to: localhost
 '''
 
-import base64
 import json
+import base64
 
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.urls import fetch_url
+from ansible.module_utils._text import to_bytes
 
 
 def request(module, url, user, oauthkey, data='', method='GET'):
-    auth = base64.encodestring('%s:%s' % (user, oauthkey)).replace('\n', '')
+    auth = base64.b64encode(to_bytes('%s:%s' % (user, oauthkey)).replace('\n', ''))
     headers = {
         'Authorization': 'Basic %s' % auth,
     }