diff --git a/README.md b/README.md
index 5283122..e71db63 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ There are other environment variables if you want to customize various things in
 | `-e TZ=<Timezone>`<br/> **Recommended** *Default: UTC* | Set your [timezone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) to make sure logs rotate at local midnight instead of at UTC midnight.
 | `-e WEBPASSWORD=<Admin password>`<br/> **Recommended** *Default: random* | http://pi.hole/admin password. Run `docker logs pihole \| grep random` to find your random pass.
 | `-e DNS1=<IP>`<br/> *Optional* *Default: 8.8.8.8* | Primary upstream DNS provider, default is google DNS
-| `-e DNS2=<IP>`<br/> *Optional* *Default: 8.8.4.4* | Secondary upstream DNS provider, default is google DNS
+| `-e DNS2=<IP>`<br/> *Optional* *Default: 8.8.4.4* | Secondary upstream DNS provider, default is google DNS, `no` if only one DNS should used
 | `-e VIRTUAL_HOST=<Custom Hostname>`<br/> *Optional* *Default: $ServerIP*   | What your web server 'virtual host' is, accessing admin through this Hostname/IP allows you to make changes to the whitelist / blacklists in addition to the default 'http://pi.hole/admin/' address
 | `-e IPv6=<True\|False>`<br/> *Optional* *Default: True* | For unraid compatibility, strips out all the IPv6 configuration from DNS/Web services when false.
 | `-e INTERFACE=<NIC>`<br/> *Advanced/Optional* | The default works fine with our basic example docker run commands.  If you're trying to use DHCP with `--net host` mode then you may have to customize this or DNSMASQ_LISTENING.
diff --git a/bash_functions.sh b/bash_functions.sh
index 710ae42..14a05e3 100644
--- a/bash_functions.sh
+++ b/bash_functions.sh
@@ -63,7 +63,11 @@ setup_dnsmasq_dns() {
         change_setting "PIHOLE_DNS_1" "${DNS1}"
     fi
     if [[ -n "$DNS2" && -z "$setupDNS2" ]] ; then
-        change_setting "PIHOLE_DNS_2" "${DNS2}"
+        if [ "$DNS2" = "no" ] ; then
+            delete_setting "PIHOLE_DNS_2"
+        else
+            change_setting "PIHOLE_DNS_2" "${DNS2}"
+        fi
     fi
 }
 
diff --git a/test/test_bash_functions.py b/test/test_bash_functions.py
index a35776a..c744fc3 100644
--- a/test/test_bash_functions.py
+++ b/test/test_bash_functions.py
@@ -55,6 +55,8 @@ def test_bad_input_to_WEB_PORT(Docker, args, expected_error):
     ('-e ServerIP="1.2.3.4" -e DNS1="1.2.3.4"',                   'custom DNS',  '1.2.3.4', '8.8.4.4' ),
     ('-e ServerIP="1.2.3.4" -e DNS2="1.2.3.4"',                   'custom DNS',  '8.8.8.8', '1.2.3.4' ),
     ('-e ServerIP="1.2.3.4" -e DNS1="1.2.3.4" -e DNS2="2.2.3.4"', 'custom DNS',  '1.2.3.4', '2.2.3.4' ),
+    ('-e ServerIP="1.2.3.4" -e DNS1="1.2.3.4" -e DNS2="no"', 'custom DNS',  '1.2.3.4', None ),
+    ('-e ServerIP="1.2.3.4" -e DNS2="no"', 'custom DNS',  '8.8.8.8', None ),
 ])
 def test_override_default_servers_with_DNS_EnvVars(Docker, args, expected_stdout, dns1, dns2):
     ''' on first boot when DNS vars are NOT set explain default google DNS settings are used
@@ -64,7 +66,7 @@ def test_override_default_servers_with_DNS_EnvVars(Docker, args, expected_stdout
     assert expected_stdout in function.stdout
 
     docker_dns_servers = Docker.run('grep "^server=" /etc/dnsmasq.d/01-pihole.conf').stdout
-    expected_servers = 'server={}\nserver={}\n'.format(dns1, dns2)
+    expected_servers = 'server={}\n'.format(dns1) if dns2 == None else 'server={}\nserver={}\n'.format(dns1, dns2)
     assert expected_servers == docker_dns_servers
 
 @pytest.mark.parametrize('args, dns1, dns2, expected_stdout', [