diff -Nru postfix-3.1.0/debian/changelog postfix-3.1.0/debian/changelog
--- postfix-3.1.0/debian/changelog	2018-01-02 12:54:35.000000000 +0000
+++ postfix-3.1.0/debian/changelog	2020-07-13 14:23:57.000000000 +0000
@@ -1,3 +1,9 @@
+postfix (3.1.0-3ubuntu0.4) xenial; urgency=medium
+
+  * d/p/fix_tls_deploy-server-cert.patch: handle missing opt arg (LP: #1881196)
+
+ -- Lucas Kanashiro <kanashiro@ubuntu.com>  Fri, 10 Jul 2020 18:14:41 -0300
+
 postfix (3.1.0-3ubuntu0.3) xenial; urgency=medium
 
   * Only run post 3.0 master.cf fixup if upgrading from version before
diff -Nru postfix-3.1.0/debian/patches/fix_tls_deploy-server-cert.patch postfix-3.1.0/debian/patches/fix_tls_deploy-server-cert.patch
--- postfix-3.1.0/debian/patches/fix_tls_deploy-server-cert.patch	1970-01-01 00:00:00.000000000 +0000
+++ postfix-3.1.0/debian/patches/fix_tls_deploy-server-cert.patch	2020-07-10 21:20:40.000000000 +0000
@@ -0,0 +1,19 @@
+Description: Fix "postfix tls deploy-server-cert"
+ It did not handle a missing optional argument.
+Author: Viktor Dukhovni
+Origin: upstream, https://github.com/vdukhovni/postfix/commit/119d6abed969b1b30c62722ae31c854b5682beae#diff-1843f98f5710e97bd063d5807334442a
+Ubuntu-Bug: LP#1881196
+Reviewed-By: Lucas Kanashiro <kanashiro@ubuntu.com>
+Last-Updated: 2020-07-10
+
+--- a/conf/postfix-tls-script
++++ b/conf/postfix-tls-script
+@@ -777,7 +777,7 @@
+ deploy_server_cert() {
+     certfile=$1; shift
+     keyfile=$1; shift
+-    deploy=$1; shift
++    case $# in 0) deploy=;; *) deploy=$1; shift;; esac
+ 
+     # Sets key_algo, key_param and cert_param
+     check_key "$keyfile" || return 1
diff -Nru postfix-3.1.0/debian/patches/series postfix-3.1.0/debian/patches/series
--- postfix-3.1.0/debian/patches/series	2018-01-02 12:54:35.000000000 +0000
+++ postfix-3.1.0/debian/patches/series	2020-07-10 21:20:40.000000000 +0000
@@ -12,3 +12,4 @@
 40_chroot_by_default.diff
 41_rmail.diff
 50_LANG.diff
+fix_tls_deploy-server-cert.patch