diff --git a/pflogsumm-1.1.5-syslog-name-underscore-fix.patch b/pflogsumm-1.1.5-syslog-name-underscore-fix.patch
new file mode 100644
index 0000000..9279bcc
--- /dev/null
+++ b/pflogsumm-1.1.5-syslog-name-underscore-fix.patch
@@ -0,0 +1,18 @@
+diff --git a/pflogsumm-1.1.5/pflogsumm.pl b/pflogsumm-1.1.5/pflogsumm.pl
+index eb527d0..7e26206 100755
+--- a/pflogsumm-1.1.5/pflogsumm.pl
++++ b/pflogsumm-1.1.5/pflogsumm.pl
+@@ -503,7 +503,12 @@ $usageMsg =
+ # Accept either "_"s or "-"s in --switches
+ foreach (@ARGV) {
+     last if($_ eq "--");
+-    tr/_/-/ if(/^--\w/);
++    if (/^--\w/)
++    {
++        my @argspl = split("=", $_, 2);
++        $argspl[0] =~ tr/_/-/;
++        $_ = join("=", @argspl);
++    }
+ }
+ 
+ # Some pre-inits for convenience
diff --git a/postfix.spec b/postfix.spec
index 37ad5fb..dad4a05 100644
--- a/postfix.spec
+++ b/postfix.spec
@@ -49,7 +49,7 @@
 Name: postfix
 Summary: Postfix Mail Transport Agent
 Version: 3.5.9
-Release: 15%{?dist}
+Release: 16%{?dist}
 Epoch: 2
 URL: http://www.postfix.org
 License: (IBM and GPLv2+) or (EPL-2.0 and GPLv2+)
@@ -100,6 +100,7 @@ Patch11: postfix-3.4.4-chroot-example-fix.patch
 Patch12: postfix-3.5.9-glibc-234-build-fix.patch
 # rhbz#1978901, sent upstream
 Patch13: postfix-3.5.9-whitespace-name-fix.patch
+Patch14: pflogsumm-1.1.5-syslog-name-underscore-fix.patch
 
 # Optional patches - set the appropriate environment variables to include
 #                    them when building the package/spec file
@@ -252,6 +253,7 @@ popd
 %patch11 -p1 -b .chroot-example-fix
 %patch12 -p1 -b .glibc-234-build-fix
 %patch13 -p1 -b .whitespace-name-fix
+%patch14 -p1 -b .pflogsumm-1.1.5-syslog-name-underscore-fix
 
 for f in README_FILES/TLS_{LEGACY_,}README TLS_ACKNOWLEDGEMENTS; do
 	iconv -f iso8859-1 -t utf8 -o ${f}{_,} &&
@@ -795,6 +797,10 @@ fi
 %endif
 
 %changelog
+* Fri Jan 28 2022 Jaroslav Škarvada <jskarvad@redhat.com> - 2:3.5.9-16
+- Fixed pflogsumm to allow underscores in the syslog_name
+  Resolves: rhbz#2043059
+
 * Tue Aug 10 2021 Mohan Boddu <mboddu@redhat.com> - 2:3.5.9-15
 - Rebuilt for IMA sigs, glibc 2.34, aarch64 flags
   Related: rhbz#1991688