diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d19df5ab..a6fd1acc 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        distro: [debian_9, debian_10, ubuntu_16, ubuntu_18, ubuntu_20, centos_7, centos_8, fedora_32, fedora_33]
+        distro: [debian_9, debian_10, debian_11, ubuntu_16, ubuntu_18, ubuntu_20, centos_7, centos_8, fedora_32, fedora_33]
     env:
       DISTRO: ${{matrix.distro}}
     steps:
diff --git a/advanced/Scripts/piholeDebug.sh b/advanced/Scripts/piholeDebug.sh
index f0a22b6d..8ea640c2 100755
--- a/advanced/Scripts/piholeDebug.sh
+++ b/advanced/Scripts/piholeDebug.sh
@@ -410,12 +410,12 @@ os_check() {
     # This function gets a list of supported OS versions from a TXT record at versions.pi-hole.net
     # and determines whether or not the script is running on one of those systems
     local remote_os_domain valid_os valid_version detected_os detected_version cmdResult digReturnCode response
-    remote_os_domain="versions.pi-hole.net"
+    remote_os_domain=${OS_CHECK_DOMAIN_NAME:-"versions.pi-hole.net"}
 
     detected_os=$(grep "\bID\b" /etc/os-release | cut -d '=' -f2 | tr -d '"')
     detected_version=$(grep VERSION_ID /etc/os-release | cut -d '=' -f2 | tr -d '"')
 
-    cmdResult="$(dig +short -t txt ${remote_os_domain} @ns1.pi-hole.net 2>&1; echo $?)"
+    cmdResult="$(dig +short -t txt "${remote_os_domain}" @ns1.pi-hole.net 2>&1; echo $?)"
     #Get the return code of the previous command (last line)
     digReturnCode="${cmdResult##*$'\n'}"
 
diff --git a/automated install/basic-install.sh b/automated install/basic-install.sh
index 96ca8c92..4212159e 100755
--- a/automated install/basic-install.sh	
+++ b/automated install/basic-install.sh	
@@ -186,12 +186,12 @@ os_check() {
         # This function gets a list of supported OS versions from a TXT record at versions.pi-hole.net
         # and determines whether or not the script is running on one of those systems
         local remote_os_domain valid_os valid_version valid_response detected_os detected_version display_warning cmdResult digReturnCode response
-        remote_os_domain="versions.pi-hole.net"
+        remote_os_domain=${OS_CHECK_DOMAIN_NAME:-"versions.pi-hole.net"}
 
         detected_os=$(grep "\bID\b" /etc/os-release | cut -d '=' -f2 | tr -d '"')
         detected_version=$(grep VERSION_ID /etc/os-release | cut -d '=' -f2 | tr -d '"')
 
-        cmdResult="$(dig +short -t txt ${remote_os_domain} @ns1.pi-hole.net 2>&1; echo $?)"
+        cmdResult="$(dig +short -t txt "${remote_os_domain}" @ns1.pi-hole.net 2>&1; echo $?)"
         # Gets the return code of the previous command (last line)
         digReturnCode="${cmdResult##*$'\n'}"
 
diff --git a/supportedos.txt b/supportedos.txt
index 6d579132..c9332deb 100644
--- a/supportedos.txt
+++ b/supportedos.txt
@@ -1,5 +1,5 @@
 Raspbian=9,10
 Ubuntu=16,18,20
-Debian=9,10
+Debian=9,10,11
 Fedora=32,33
-CentOS=7,8
\ No newline at end of file
+CentOS=7,8
diff --git a/test/_debian_11.Dockerfile b/test/_debian_11.Dockerfile
new file mode 100644
index 00000000..39be027e
--- /dev/null
+++ b/test/_debian_11.Dockerfile
@@ -0,0 +1,17 @@
+FROM buildpack-deps:bullseye-scm
+
+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
+ENV OS_CHECK_DOMAIN_NAME dev-supportedos.pi-hole.net
+
+#sed '/# Start the installer/Q' /opt/pihole/basic-install.sh > /opt/pihole/stub_basic-install.sh && \
diff --git a/test/tox.debian_11.ini b/test/tox.debian_11.ini
new file mode 100644
index 00000000..af3c6e36
--- /dev/null
+++ b/test/tox.debian_11.ini
@@ -0,0 +1,8 @@
+[tox]
+envlist = py37
+
+[testenv]
+whitelist_externals = docker
+deps = -rrequirements.txt
+commands = docker build -f _debian_11.Dockerfile -t pytest_pihole:test_container ../
+           pytest {posargs:-vv -n auto} ./test_automated_install.py