diff --git a/source/installation-guide/debian-9.rst b/source/installation-guide/debian-9.rst
new file mode 100644
--- /dev/null
+++ b/source/installation-guide/debian-9.rst
@@ -0,0 +1,50 @@
+.. _installation-guide-debian-9:
+
+====================================
+Installation of Kolab 16 on Debian 9
+====================================
+
+.. WARNING::
+
+    This document sets you up with the version of Kolab that is maintained by
+    the community. Customers of `Kolab Systems AG`_ join us
+    :ref:`here <installation-guide-debian-9-enterprise-16>`.
+
+1.  Add the following two lines to ``/etc/apt/sources.list.d/kolab.list``:
+
+    .. parsed-literal::
+
+        deb http://obs.kolabsys.com/repositories/Kolab:/16/Debian_9.0/ ./
+        deb-src http://obs.kolabsys.com/repositories/Kolab:/16/Debian_9.0/ ./
+
+2.  Import the GPG key used to sign the packages:
+
+    .. parsed-literal::
+
+        # :command:`wget -q -O- https://ssl.kolabsys.com/community.asc | apt-key add -`
+
+3.  To ensure the Kolab packages have priority over the Debian packages, such as
+    must be the case for PHP as well as Cyrus IMAP, please make sure the APT
+    preferences pin the obs.kolabsys.com origin as a preferred source.
+
+    Put the following in ``/etc/apt/preferences.d/kolab``:
+
+    .. parsed-literal::
+
+        Package: *
+        Pin: origin obs.kolabsys.com
+        Pin-Priority: 501
+
+4.  Update the repository metadata:
+
+    .. parsed-literal::
+
+        # :command:`apt-get update`
+
+5. Start the installation of the base package as follows:
+
+    .. parsed-literal::
+
+        # :command:`aptitude -y install kolab`
+
+Continue to :ref:`installation-guide-setup-kolab`.
diff --git a/source/installation-guide/index.rst b/source/installation-guide/index.rst
--- a/source/installation-guide/index.rst
+++ b/source/installation-guide/index.rst
@@ -42,6 +42,7 @@
     centos-7
     rhel-7
     debian-8
+    debian-9
     ubuntu-16.04
 
 If your personal favorite is not listed, please read the
diff --git a/source/installation-guide/kolab-16/debian-9.rst b/source/installation-guide/kolab-16/debian-9.rst
new file mode 100644
--- /dev/null
+++ b/source/installation-guide/kolab-16/debian-9.rst
@@ -0,0 +1,99 @@
+.. _installation-guide-debian-9-enterprise-16:
+
+==============================================
+Installation of Kolab 16 on Debian 9 (Stretch)
+==============================================
+
+1.  Install the **apt-transport-https** package:
+
+    .. parsed-literal::
+
+        # :command:`aptitude -y install apt-transport-https`
+
+2.  Add the following two lines to ``/etc/apt/sources.list.d/kolab.list``:
+
+    .. parsed-literal::
+
+        deb https://mirror.kolabenterprise.com/debian/kolab-16/ stretch release updates
+        deb-src https://mirror.kolabenterprise.com/debian/kolab-16/ stretch release updates
+
+3.  To ensure the Kolab packages have priority over the Debian packages, such as
+    must be the case for PHP as well as Cyrus IMAP, please make sure the APT
+    preferences pin the mirror.kolabsys.com origin as a preferred source.
+
+    Put the following in ``/etc/apt/preferences.d/kolab``:
+
+    .. parsed-literal::
+
+        Package: *
+        Pin: origin mirror.kolabenterprise.com
+        Pin-Priority: 501
+
+4.  Install the client certificate and certificate authority files:
+
+    A.  Remove the passphrase from the SSL certificate key:
+
+        .. parsed-literal::
+
+            # :command:`openssl rsa -in /path/to/private.key \\
+                -out /path/to/private.key.nopass`
+
+    B.  Concatenate the certificate file and the new key file without
+        passphrase:
+
+        .. parsed-literal::
+
+            # :command:`cat /path/to/public.crt /path/to/private.key.nopass \\
+                > /path/to/mirror.kolabsys.com.client.pem`
+
+    C.  Place the file :file:`mirror.kolabsys.client.pem` in
+        :file:`/etc/apt/certs/`.
+
+    D. Download the kolabenterprice mirror certificate:
+
+        .. parsed-literal::
+
+            # :command:`cd /etc/apt/certs/`
+            # :command:`wget https://ssl.kolabsys.com/mirror.kolabenterprise.com.ca.cert`
+
+    E. Correct the permissions on the private key:
+
+        .. parsed-literal::
+
+            # :command:`chown root:root /etc/apt/certs/mirror.kolabsys.com.client.pem`
+            # :command:`chmod 640 /etc/apt/certs/mirror.kolabsys.com.client.pem`
+
+5.  Configure **APT** to use the certificates installed in step 4 by
+    creating a file ``/etc/apt/apt.conf.d/81kolab`` with the following
+    contents:
+
+    .. parsed-literal::
+
+        Acquire {
+            https {
+                mirror.kolabenterprise.com {
+                    Verify-Peer "true";
+                    Verify-Host "true";
+                    CaInfo "/etc/apt/certs/mirror.kolabenterprise.com.ca.cert";
+
+                    SslCert "/etc/apt/certs/mirror.kolabsys.com.client.pem";
+                    SslKey "/etc/apt/certs/mirror.kolabsys.com.client.pem";
+                };
+            };
+        };
+
+6.  Update the repository metadata:
+
+    .. parsed-literal::
+
+        # :command:`apt-get update`
+
+7.  Start the installation of the base package as follows:
+
+    .. parsed-literal::
+
+        # :command:`aptitude install kolab`
+
+8.  When asked to confirm you want to install the package and its dependencies, press Enter.
+
+Continue to :ref:`installation-guide-setup-kolab`.