diff --git a/test/centos.Dockerfile b/test/centos.Dockerfile
index 00543b67..7444551b 100644
--- a/test/centos.Dockerfile
+++ b/test/centos.Dockerfile
@@ -1,4 +1,4 @@
-FROM centos:7
+FROM centos:8
 
 ENV GITDIR /etc/.pihole
 ENV SCRIPTDIR /opt/pihole
diff --git a/test/centos7.Dockerfile b/test/centos7.Dockerfile
new file mode 100644
index 00000000..00543b67
--- /dev/null
+++ b/test/centos7.Dockerfile
@@ -0,0 +1,16 @@
+FROM centos:7
+
+ENV GITDIR /etc/.pihole
+ENV SCRIPTDIR /opt/pihole
+
+RUN mkdir -p $GITDIR $SCRIPTDIR /etc/pihole
+ADD . $GITDIR
+RUN cp $GITDIR/advanced/Scripts/*.sh $GITDIR/gravity.sh $GITDIR/pihole $GITDIR/automated\ install/*.sh $SCRIPTDIR/
+ENV PATH /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:$SCRIPTDIR
+
+RUN true && \
+    chmod +x $SCRIPTDIR/*
+
+ENV PH_TEST true
+
+#sed '/# Start the installer/Q' /opt/pihole/basic-install.sh > /opt/pihole/stub_basic-install.sh && \
diff --git a/test/conftest.py b/test/conftest.py
index 5b8be41e..69926eaf 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -69,7 +69,7 @@ def args(request):
     return '-t -d'
 
 
-@pytest.fixture(params=['debian', 'centos', 'fedora'])
+@pytest.fixture(params=['debian', 'centos7', 'centos', 'fedora'])
 def tag(request):
     '''
     consumed by image to make the test matrix
diff --git a/test/debian.Dockerfile b/test/debian.Dockerfile
index 66436f1a..d6609ba3 100644
--- a/test/debian.Dockerfile
+++ b/test/debian.Dockerfile
@@ -1,4 +1,4 @@
-FROM buildpack-deps:jessie-scm
+FROM buildpack-deps:stretch-scm
 
 ENV GITDIR /etc/.pihole
 ENV SCRIPTDIR /opt/pihole
diff --git a/test/fedora.Dockerfile b/test/fedora.Dockerfile
index a06fc007..02dcb733 100644
--- a/test/fedora.Dockerfile
+++ b/test/fedora.Dockerfile
@@ -1,4 +1,4 @@
-FROM fedora:30
+FROM fedora:31
 
 ENV GITDIR /etc/.pihole
 ENV SCRIPTDIR /opt/pihole
diff --git a/test/test_000_build_containers.py b/test/test_000_build_containers.py
index 184052f3..0f3e2d1a 100644
--- a/test/test_000_build_containers.py
+++ b/test/test_000_build_containers.py
@@ -9,6 +9,7 @@ run_local = testinfra.get_backend(
 
 @pytest.mark.parametrize("image,tag", [
     ('test/debian.Dockerfile', 'pytest_pihole:debian'),
+    ('test/centos7.Dockerfile', 'pytest_pihole:centos7'),
     ('test/centos.Dockerfile', 'pytest_pihole:centos'),
     ('test/fedora.Dockerfile', 'pytest_pihole:fedora'),
 ])
diff --git a/test/test_automated_install.py b/test/test_automated_install.py
index 342d8a3c..f6b5a87e 100644
--- a/test/test_automated_install.py
+++ b/test/test_automated_install.py
@@ -561,3 +561,37 @@ def test_validate_ip_invalid_letters(Pihole):
     ''')
 
     assert output.rc == 1
+
+
+def test_os_check_fails(Pihole):
+    ''' Confirms install fails on unsupported OS '''
+    Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    install_dependent_packages ${INSTALLER_DEPS[@]}
+    cat <<EOT > /etc/os-release
+    ID=UnsupportedOS
+    VERSION_ID="2"
+    EOT
+    ''')
+    detectOS = Pihole.run('''t
+    source /opt/pihole/basic-install.sh
+    os_check
+    ''')
+    expected_stdout = 'Unsupported OS detected: UnsupportedOS'
+    assert expected_stdout in detectOS.stdout
+
+
+def test_os_check_passes(Pihole):
+    ''' Confirms OS meets the requirements '''
+    Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    install_dependent_packages ${INSTALLER_DEPS[@]}
+    ''')
+    detectOS = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    os_check
+    ''')
+    expected_stdout = 'Supported OS detected'
+    assert expected_stdout in detectOS.stdout
diff --git a/test/test_centos_fedora_support.py b/test/test_centos_fedora_support.py
index 4b405920..b4ae7c89 100644
--- a/test/test_centos_fedora_support.py
+++ b/test/test_centos_fedora_support.py
@@ -88,7 +88,7 @@ def test_epel_and_remi_not_installed_fedora(Pihole):
     assert not remi_package.is_installed
 
 
-@pytest.mark.parametrize("tag", [('centos'), ])
+@pytest.mark.parametrize("tag", [('centos7'), ('centos'), ])
 def test_release_supported_version_check_centos(Pihole):
     '''
     confirms installer exits on unsupported releases of CentOS
@@ -105,7 +105,7 @@ def test_release_supported_version_check_centos(Pihole):
     assert expected_stdout in distro_check.stdout
 
 
-@pytest.mark.parametrize("tag", [('centos'), ])
+@pytest.mark.parametrize("tag", [('centos7'), ('centos'), ])
 def test_enable_epel_repository_centos(Pihole):
     '''
     confirms the EPEL package repository is enabled when installed on CentOS
@@ -123,8 +123,8 @@ def test_enable_epel_repository_centos(Pihole):
     assert epel_package.is_installed
 
 
-@pytest.mark.parametrize("tag", [('centos'), ])
-def test_php_upgrade_default_optout_centos(Pihole):
+@pytest.mark.parametrize("tag", [('centos7'), ])
+def test_php_upgrade_default_optout_centos_eq_7(Pihole):
     '''
     confirms the default behavior to opt-out of installing PHP7 from REMI
     '''
@@ -140,7 +140,25 @@ def test_php_upgrade_default_optout_centos(Pihole):
 
 
 @pytest.mark.parametrize("tag", [('centos'), ])
-def test_php_upgrade_user_optout_centos(Pihole):
+def test_php_upgrade_default_continue_centos_gte_8(Pihole):
+    '''
+    confirms the latest version of CentOS continues / does not optout
+    (should trigger on CentOS7 only)
+    '''
+    distro_check = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    ''')
+    unexpected_stdout = info_box + (' User opt-out of PHP 7 upgrade on CentOS.'
+                                    ' Deprecated PHP may be in use.')
+    assert unexpected_stdout not in distro_check.stdout
+    # ensure remi was not installed on latest CentOS
+    remi_package = Pihole.package('remi-release')
+    assert not remi_package.is_installed
+
+
+@pytest.mark.parametrize("tag", [('centos7'), ])
+def test_php_upgrade_user_optout_centos_eq_7(Pihole):
     '''
     confirms installer behavior when user opt-out of installing PHP7 from REMI
     (php not currently installed)
@@ -159,7 +177,28 @@ def test_php_upgrade_user_optout_centos(Pihole):
 
 
 @pytest.mark.parametrize("tag", [('centos'), ])
-def test_php_upgrade_user_optin_centos(Pihole):
+def test_php_upgrade_user_optout_skipped_centos_gte_8(Pihole):
+    '''
+    confirms installer skips user opt-out of installing PHP7 from REMI on
+    latest CentOS (should trigger on CentOS7 only)
+    (php not currently installed)
+    '''
+    # Whiptail dialog returns Cancel for user prompt
+    mock_command('whiptail', {'*': ('', '1')}, Pihole)
+    distro_check = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    ''')
+    unexpected_stdout = info_box + (' User opt-out of PHP 7 upgrade on CentOS.'
+                                    ' Deprecated PHP may be in use.')
+    assert unexpected_stdout not in distro_check.stdout
+    # ensure remi was not installed on latest CentOS
+    remi_package = Pihole.package('remi-release')
+    assert not remi_package.is_installed
+
+
+@pytest.mark.parametrize("tag", [('centos7'), ])
+def test_php_upgrade_user_optin_centos_eq_7(Pihole):
     '''
     confirms installer behavior when user opt-in to installing PHP7 from REMI
     (php not currently installed)
@@ -182,6 +221,30 @@ def test_php_upgrade_user_optin_centos(Pihole):
 
 
 @pytest.mark.parametrize("tag", [('centos'), ])
+def test_php_upgrade_user_optin_skipped_centos_gte_8(Pihole):
+    '''
+    confirms installer skips user opt-in to installing PHP7 from REMI on
+    latest CentOS (should trigger on CentOS7 only)
+    (php not currently installed)
+    '''
+    # Whiptail dialog returns Continue for user prompt
+    mock_command('whiptail', {'*': ('', '0')}, Pihole)
+    distro_check = Pihole.run('''
+    source /opt/pihole/basic-install.sh
+    distro_check
+    ''')
+    assert 'opt-out' not in distro_check.stdout
+    unexpected_stdout = info_box + (' Enabling Remi\'s RPM repository '
+                                    '(https://rpms.remirepo.net)')
+    assert unexpected_stdout not in distro_check.stdout
+    unexpected_stdout = tick_box + (' Remi\'s RPM repository has '
+                                    'been enabled for PHP7')
+    assert unexpected_stdout not in distro_check.stdout
+    remi_package = Pihole.package('remi-release')
+    assert not remi_package.is_installed
+
+
+@pytest.mark.parametrize("tag", [('centos7'), ('centos'), ])
 def test_php_version_lt_7_detected_upgrade_default_optout_centos(Pihole):
     '''
     confirms the default behavior to opt-out of upgrading to PHP7 from REMI
@@ -204,7 +267,7 @@ def test_php_version_lt_7_detected_upgrade_default_optout_centos(Pihole):
     assert not remi_package.is_installed
 
 
-@pytest.mark.parametrize("tag", [('centos'), ])
+@pytest.mark.parametrize("tag", [('centos7'), ('centos'), ])
 def test_php_version_lt_7_detected_upgrade_user_optout_centos(Pihole):
     '''
     confirms installer behavior when user opt-out to upgrade to PHP7 via REMI
@@ -229,7 +292,7 @@ def test_php_version_lt_7_detected_upgrade_user_optout_centos(Pihole):
     assert not remi_package.is_installed
 
 
-@pytest.mark.parametrize("tag", [('centos'), ])
+@pytest.mark.parametrize("tag", [('centos7'), ('centos'), ])
 def test_php_version_lt_7_detected_upgrade_user_optin_centos(Pihole):
     '''
     confirms installer behavior when user opt-in to upgrade to PHP7 via REMI
diff --git a/tox.ini b/tox.ini
index 249575b6..49c99066 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,10 +1,11 @@
 [tox]
-envlist = py36
+envlist = py37
 
 [testenv]
 whitelist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f test/debian.Dockerfile -t pytest_pihole:debian .
+           docker build -f test/centos7.Dockerfile -t pytest_pihole:centos7 .
            docker build -f test/centos.Dockerfile -t pytest_pihole:centos .
            docker build -f test/fedora.Dockerfile -t pytest_pihole:fedora .
            pytest {posargs:-vv -n auto} -m "not build_stage" ./test/