diff --git a/printrun-flush.patch b/printrun-flush.patch
new file mode 100644
index 0000000..3300753
--- /dev/null
+++ b/printrun-flush.patch
@@ -0,0 +1,25 @@
+From f57eb1d4876db59683e396c9077a49224c7ce573 Mon Sep 17 00:00:00 2001
+From: Guillaume Seguin <guillaume@segu.in>
+Date: Thu, 20 Jun 2013 14:30:01 +0200
+Subject: [PATCH] Only flush TCP connections, not serial ones (fix #402)
+
+---
+ printcore.py | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/printcore.py b/printcore.py
+index 2b74022..d9dafa7 100755
+--- a/printcore.py
++++ b/printcore.py
+@@ -523,7 +523,7 @@ def _send(self, command, lineno = 0, calcchecksum = False):
+                 except: pass
+             try:
+                 self.printer.write(str(command + "\n"))
+-                self.printer.flush()
++                if self.printer_tcp: self.printer.flush()
+                 self.writefailures = 0
+             except socket.error as e:
+                 print "Can't write to printer (disconnected?) (Socket error {0}): {1}".format(e.errno, e.strerror)
+-- 
+1.8.1.6
+
diff --git a/printrun.spec b/printrun.spec
index 40e6d37..806d535 100644
--- a/printrun.spec
+++ b/printrun.spec
@@ -7,7 +7,7 @@
 %global prontserve 0
 Name:           printrun
 Version:        0.0
-Release:        26.%{snapshot}%{?dist}
+Release:        27.%{snapshot}%{?dist}
 Summary:        RepRap printer interface and tools
 License:        GPLv3+
 Group:          Applications/Engineering
@@ -21,6 +21,9 @@ Source3:        plater.desktop
 
 Patch0:         %{name}-plater-not-installed.patch
 
+# https://github.com/kliment/Printrun/issues/402
+Patch1:         %{name}-flush.patch
+
 BuildArch:      noarch
 BuildRequires:  python2-devel
 BuildRequires:  desktop-file-utils
@@ -104,6 +107,7 @@ It is a part of Printrun.
 %prep
 %setup -qn Printrun-%{commit}
 %patch0 -p1
+%patch1 -p1
 
 # use launchers for skeinforge
 sed -i 's|python skeinforge/skeinforge_application/skeinforge.py|skeinforge|' pronsole.py
@@ -181,6 +185,9 @@ rm -f %{buildroot}%{_bindir}/prontserve.*
 %doc README* COPYING
 
 %changelog
+* Thu Jun 20 2013 Miro Hrončok <mhroncok@redhat.com> - 0.0-27.20130604git80e313d
+- Added patch to solve upstream issue 402
+
 * Tue Jun 18 2013 Miro Hrončok <mhroncok@redhat.com> - 0.0-26.20130604git80e313d
 - Upstream released tag release 20130604
 - Pyglet 1.2 issue fixed in upstream, removed patch