diff --git a/changelogs/fragments/fix_cli_ssh_defaults.yml b/changelogs/fragments/fix_cli_ssh_defaults.yml
new file mode 100644
index 00000000000..65d26768c9c
--- /dev/null
+++ b/changelogs/fragments/fix_cli_ssh_defaults.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - cli defaults for ssh args set to None as '' was bypassing normal default.
diff --git a/lib/ansible/cli/arguments/option_helpers.py b/lib/ansible/cli/arguments/option_helpers.py
index dc3a88b53cb..7492e781c55 100644
--- a/lib/ansible/cli/arguments/option_helpers.py
+++ b/lib/ansible/cli/arguments/option_helpers.py
@@ -261,13 +261,13 @@ def add_connect_options(parser):
                                help="override the connection timeout in seconds (default=%s)" % C.DEFAULT_TIMEOUT)
 
     # ssh only
-    connect_group.add_argument('--ssh-common-args', default='', dest='ssh_common_args',
+    connect_group.add_argument('--ssh-common-args', default=None, dest='ssh_common_args',
                                help="specify common arguments to pass to sftp/scp/ssh (e.g. ProxyCommand)")
-    connect_group.add_argument('--sftp-extra-args', default='', dest='sftp_extra_args',
+    connect_group.add_argument('--sftp-extra-args', default=None, dest='sftp_extra_args',
                                help="specify extra arguments to pass to sftp only (e.g. -f, -l)")
-    connect_group.add_argument('--scp-extra-args', default='', dest='scp_extra_args',
+    connect_group.add_argument('--scp-extra-args', default=None, dest='scp_extra_args',
                                help="specify extra arguments to pass to scp only (e.g. -l)")
-    connect_group.add_argument('--ssh-extra-args', default='', dest='ssh_extra_args',
+    connect_group.add_argument('--ssh-extra-args', default=None, dest='ssh_extra_args',
                                help="specify extra arguments to pass to ssh only (e.g. -R)")
 
     parser.add_argument_group(connect_group)
diff --git a/lib/ansible/plugins/connection/ssh.py b/lib/ansible/plugins/connection/ssh.py
index be371900522..3f812c1cb18 100644
--- a/lib/ansible/plugins/connection/ssh.py
+++ b/lib/ansible/plugins/connection/ssh.py
@@ -92,6 +92,7 @@ DOCUMENTATION = '''
               - name: ansible_ssh_common_args
           cli:
               - name: ssh_common_args
+          default: ''
       ssh_executable:
           default: ssh
           description:
@@ -141,6 +142,7 @@ DOCUMENTATION = '''
               version_added: '2.7'
           cli:
             - name: scp_extra_args
+          default: ''
       sftp_extra_args:
           description: Extra exclusive to the ``sftp`` CLI
           vars:
@@ -154,8 +156,10 @@ DOCUMENTATION = '''
               version_added: '2.7'
           cli:
             - name: sftp_extra_args
+          default: ''
       ssh_extra_args:
           description: Extra exclusive to the 'ssh' CLI
+          default: ''
           vars:
               - name: ansible_ssh_extra_args
           env: