diff --git a/roles/backup_client/handlers/main.yml b/roles/backup_client/handlers/main.yml
index 94b2a14452c82e26591dae129aaaeec9c1255582..57fc94ec6507739f3612516dcde885616371387d 100644
--- a/roles/backup_client/handlers/main.yml
+++ b/roles/backup_client/handlers/main.yml
@@ -1,8 +1,7 @@
 ---
 
-# Can't use file module, since one of the files (GnuPG socket)
-# seems to disappear in middle of operation). This is change between
-# Jessie and Stretch.
+# @TODO: Can't use file module, since one of the files (GnuPG socket)
+#        seems to disappear in middle of operation).
 - name: Remove current keyring
   command: "rm -rf /etc/duply/main/gnupg"
   args:
diff --git a/roles/backup_server/molecule/default/tests/data/ssh/known_hosts b/roles/backup_server/molecule/default/tests/data/ssh/known_hosts
index 2be22a5c806104ea16fad7299366d9efe4deb328..f7eacc817540e06feb73cc28c576346984023c67 100644
--- a/roles/backup_server/molecule/default/tests/data/ssh/known_hosts
+++ b/roles/backup_server/molecule/default/tests/data/ssh/known_hosts
@@ -1,13 +1,3 @@
-# Jessie.
-[10.31.127.10]:2222 ssh-dss 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
-[10.31.127.10]:2222 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC2SqbwZNanhTMM8wL1iGtNOR7nYbXcCQNbU65crXN43W1tz4GXoyluHEEXs0we7jmZZyow19X89Ve5w8ODL42KRDtNXoN8wjoLwZ1l7iGsrN1oUXJP7i6i9lH/0F+fudFB3Tm53ieBr0MEMdxAQBpk+MCi64G0iuvZeE0sKG5JfSky82ZZ26m5EchORJuiiKObB17EsUGl091S8eiLXIIiQQvg4d9933oAqNCLe0uxbNfJcbMJAdr+m9rYxyVoPXweUm1beb/6/vZQzAf0HL5+Ic/mbLu3z4httCh0dIlCqjRe/8llqF21psIlN8D8hZkzY6WEo7/v9wHAGFTFFFlJ
-[10.31.127.10]:2222 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBLaZb8xcw5PbzQ8Jo8xygcUaI6ziGLs+ZqsAqJSOIou9iN0zSKO9a4ujbeMgIbfZZPB5UWcv1CxNekTZ4tkrAaM=
-[10.31.127.10]:2222 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOQzNj16lZ3ucIJvwnFYzR/vZT3SuWiIVPNOhK5JGlq6
-[10.31.127.11]:2222 ssh-dss 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
-[10.31.127.11]:2222 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC2SqbwZNanhTMM8wL1iGtNOR7nYbXcCQNbU65crXN43W1tz4GXoyluHEEXs0we7jmZZyow19X89Ve5w8ODL42KRDtNXoN8wjoLwZ1l7iGsrN1oUXJP7i6i9lH/0F+fudFB3Tm53ieBr0MEMdxAQBpk+MCi64G0iuvZeE0sKG5JfSky82ZZ26m5EchORJuiiKObB17EsUGl091S8eiLXIIiQQvg4d9933oAqNCLe0uxbNfJcbMJAdr+m9rYxyVoPXweUm1beb/6/vZQzAf0HL5+Ic/mbLu3z4httCh0dIlCqjRe/8llqF21psIlN8D8hZkzY6WEo7/v9wHAGFTFFFlJ
-[10.31.127.11]:2222 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBLaZb8xcw5PbzQ8Jo8xygcUaI6ziGLs+ZqsAqJSOIou9iN0zSKO9a4ujbeMgIbfZZPB5UWcv1CxNekTZ4tkrAaM=
-[10.31.127.11]:2222 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOQzNj16lZ3ucIJvwnFYzR/vZT3SuWiIVPNOhK5JGlq6
-
 # Stretch
 [10.31.127.20]:2222 ssh-dss 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
 [10.31.127.20]:2222 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC2SqbwZNanhTMM8wL1iGtNOR7nYbXcCQNbU65crXN43W1tz4GXoyluHEEXs0we7jmZZyow19X89Ve5w8ODL42KRDtNXoN8wjoLwZ1l7iGsrN1oUXJP7i6i9lH/0F+fudFB3Tm53ieBr0MEMdxAQBpk+MCi64G0iuvZeE0sKG5JfSky82ZZ26m5EchORJuiiKObB17EsUGl091S8eiLXIIiQQvg4d9933oAqNCLe0uxbNfJcbMJAdr+m9rYxyVoPXweUm1beb/6/vZQzAf0HL5+Ic/mbLu3z4httCh0dIlCqjRe/8llqF21psIlN8D8hZkzY6WEo7/v9wHAGFTFFFlJ
diff --git a/roles/mail_server/molecule/default/tests/test_mandatory.py b/roles/mail_server/molecule/default/tests/test_mandatory.py
index 538686361642479f14afc1fb57fb4e3d88a90cf1..048fba86a4fef7305ca352d4bdff2201983ecdde 100644
--- a/roles/mail_server/molecule/default/tests/test_mandatory.py
+++ b/roles/mail_server/molecule/default/tests/test_mandatory.py
@@ -161,14 +161,10 @@ def test_imap_tls_configuration(host):
     # Test TLS protocol versions.
     starttls_old_tls_versions_disabled = host.run("echo 'a0001 LOGOUT' | openssl s_client -quiet -starttls imap -no_tls1_2 -connect parameters-mandatory:143")
     assert starttls_old_tls_versions_disabled.rc != 0
-    # First error message from OpenSSL in Debian 8 Jessie, second from
-    # OpenSSL in Debian 9 Stretch.
     assert "write:errno=104" in starttls_old_tls_versions_disabled.stderr or 'SSL alert number 70' in starttls_old_tls_versions_disabled.stderr
 
     tls_old_tls_versions_disabled = host.run("echo 'a0001 LOGOUT' | openssl s_client -quiet -no_tls1_2 -connect parameters-mandatory:993")
     assert tls_old_tls_versions_disabled.rc != 0
-    # First error message from OpenSSL in Debian 8 Jessie, second from
-    # OpenSSL in Debian 9 Stretch.
     assert "write:errno=104" in tls_old_tls_versions_disabled.stderr or 'SSL alert number 70' in tls_old_tls_versions_disabled.stderr
 
     # Test at least one strong TLS cipher.
@@ -242,8 +238,6 @@ def test_postfix_tls_configuration(host):
 
     starttls = host.run("echo 'QUIT' | openssl s_client -quiet -starttls smtp -no_tls1_2 -connect parameters-mandatory:587")
     assert starttls.rc != 0
-    # First error message from OpenSSL in Debian 8 Jessie, second from
-    # OpenSSL in Debian 9 Stretch.
     assert 'write:errno=104' in starttls.stderr or 'SSL alert number 70' in starttls.stderr
 
     # Test ciphers for default port (less restrictive).
diff --git a/roles/preseed/templates/preseed.cfg.j2 b/roles/preseed/templates/preseed.cfg.j2
index 10037d7c59442f945e8da42387d1f04bbcf67c5e..7a6eb9a0a932f141ad84c502437249c0bad9dc41 100644
--- a/roles/preseed/templates/preseed.cfg.j2
+++ b/roles/preseed/templates/preseed.cfg.j2
@@ -1,7 +1,7 @@
 {% set overrides = preseed_server_overrides[item] | default({}) %}
 {% set network_auto = overrides["network_auto"] | default(preseed_network_auto) %}
 #
-# Pressed configuration file for Debian Jessie/Stretch installation for server {{ item }}.
+# Pressed configuration file for Debian Stretch installation for server {{ item }}.
 #