diff --git a/postfix-3.5.4.tar.gz b/postfix-3.5.4.tar.gz
deleted file mode 100644
index 66372cf..0000000
--- a/postfix-3.5.4.tar.gz
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:fc2fb1cc27556aa2506bc287af04881cde07c83d5cb213ba835083b4bb796881
-size 4612431
diff --git a/postfix-3.5.4.tar.gz.sig b/postfix-3.5.4.tar.gz.sig
deleted file mode 100644
index f8260ed..0000000
--- a/postfix-3.5.4.tar.gz.sig
+++ /dev/null
@@ -1,7 +0,0 @@
------BEGIN PGP SIGNATURE-----
-Version: GnuPG v2.0.18 (FreeBSD)
-
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-NC1EYzCAEQD9ESyfNr2ZMS2iRsFqIiNM+h49AkYEKxQRYTeoGap2mRs=
-=kaGS
------END PGP SIGNATURE-----
diff --git a/postfix-3.5.6.tar.gz b/postfix-3.5.6.tar.gz
new file mode 100644
index 0000000..cac66b6
--- /dev/null
+++ b/postfix-3.5.6.tar.gz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ec0aa671582adce157675e15da1dfa7ac2b5ff653571addba643735d0ec1e6a
+size 4613310
diff --git a/postfix-3.5.6.tar.gz.asc b/postfix-3.5.6.tar.gz.asc
new file mode 100644
index 0000000..0dcb215
--- /dev/null
+++ b/postfix-3.5.6.tar.gz.asc
@@ -0,0 +1,7 @@
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v2.0.18 (FreeBSD)
+
+iFcDBQBfHc4XDAtZDoDKFacRCiw2AP9m1yhRThx0RH5l+k4OPsDbq/nfw26pwc1I
+ZRwjaNdF6wD/V1adfIZielz+McnWesIrG/51T4CFZkk2EwG2e4pZ1fI=
+=OX/E
+-----END PGP SIGNATURE-----
diff --git a/postfix.changes b/postfix.changes
index bfb5f5e..febff61 100644
--- a/postfix.changes
+++ b/postfix.changes
@@ -1,3 +1,20 @@
+-------------------------------------------------------------------
+Sun Aug  9 06:55:01 UTC 2020 - Arjen de Korte <suse+build@de-korte.org>
+
+- Use the correct signature file for source verification
+- Rename postfix-3.5.6.tar.gz.sig to postfix-3.5.6.tar.gz.asc (to
+  prevent confusion, as the signature file from upstream with .sig
+  extension is incompatible with the build service)
+
+-------------------------------------------------------------------
+Sun Jul 26 21:22:39 UTC 2020 - Michael Ströder <michael@stroeder.com>
+
+- Update to 3.5.6 with following fixes:
+  * Workaround for unexpected TLS interoperability problems when Postfix
+    runs on OS distributions with system-wide OpenSSL configurations.
+  * Memory leaks in the Postfix TLS library, the largest one
+    involving multiple kBytes per peer certificate.
+
 -------------------------------------------------------------------
 Thu Jul 16 20:42:19 UTC 2020 - Arjen de Korte <suse+build@de-korte.org>
 
diff --git a/postfix.spec b/postfix.spec
index a2c569f..6db4ede 100644
--- a/postfix.spec
+++ b/postfix.spec
@@ -53,14 +53,14 @@
 %bcond_with    libnsl
 %endif
 Name:           postfix
-Version:        3.5.4
+Version:        3.5.6
 Release:        0
 Summary:        A fast, secure, and flexible mailer
 License:        IPL-1.0 OR EPL-2.0
 Group:          Productivity/Networking/Email/Servers
 URL:            http://www.postfix.org
 Source0:        http://cdn.postfix.johnriley.me/mirrors/postfix-release/official/postfix-%{version}.tar.gz
-Source1:        http://cdn.postfix.johnriley.me/mirrors/postfix-release/official/postfix-%{version}.tar.gz.gpg2#/postfix-%{version}.tar.gz.sig
+Source1:        http://cdn.postfix.johnriley.me/mirrors/postfix-release/official/postfix-%{version}.tar.gz.gpg2#/postfix-%{version}.tar.gz.asc
 Source2:        %{name}-SUSE.tar.gz
 Source3:        %{name}-mysql.tar.bz2
 #Source4:        http://cdn.postfix.johnriley.me/mirrors/postfix-release/wietse.pgp#/postfix.keyring