diff --git a/office/ganttproject/build.xml.patch b/office/ganttproject/build.xml.patch
index 4c9e386642..e21d7c09cb 100644
--- a/office/ganttproject/build.xml.patch
+++ b/office/ganttproject/build.xml.patch
@@ -1,6 +1,6 @@
---- ganttproject-builder/build.xml	2017-03-06 17:21:28.000000000 +0300
-+++ build.xml	2016-07-26 14:21:14.000000000 +0300
-@@ -1,130 +1,370 @@
+--- ganttproject-builder/build.xml	2017-03-24 19:03:16.000000000 +0300
++++ build.xml	2017-04-27 12:07:19.410170289 +0300
+@@ -1,137 +1,370 @@
 -<project name="GanttProject builder">
 -    <property file="build-deb.properties"/>
 -    <path id="class.path">
@@ -93,6 +93,7 @@
 -
 -    <target name="distMac" depends="distBin">
 -        <mkdir dir="${distMacWork}"/>
+-
 -        <bundleapp outputdirectory="${distMacWork}"
 -                   name="GanttProject"
 -                   displayname="GanttProject"
@@ -103,7 +104,9 @@
 -                   applicationCategory="public.app-category.productivity"
 -                   mainclassname="org.bardsoftware.eclipsito.Boot">
 -
--            <classpath file="eclipsito.jar"/>
+-            <classpath dir=".">
+-              <include name="eclipsito.jar"/>
+-            </classpath>
 -            <argument value="-app"/>
 -            <argument value="net.sourceforge.ganttproject.GanttProject"/>
 -            <argument value="-plugins-dir"/>
@@ -123,10 +126,14 @@
 -                <include name="logging.properties"/>
 -            </fileset>
 -        </copy>
+-        <copy todir="${distMacWork}" file="HouseBuildingSample.gan"/>
 -        <patch patchfile="Info.plist.patch" originalfile="${distMacWork}/GanttProject.app/Contents/Info.plist"/>
+-
+-        <mkdir dir="${distMacWork}/GanttProject.app/Contents/Java/Classes"/>
+-        <copy todir="${distMacWork}/GanttProject.app/Contents/Java/Classes" file="logging.properties"/>
 -        <chmod perm="a+rx" file="${distMacWork}/GanttProject.app/Contents/MacOS/JavaAppLauncher"></chmod>
 -        <zip destfile="${distMacZip}">
--            <zipfileset dir="${distMacWork}" includes="GanttProject.app/**">
+-            <zipfileset dir="${distMacWork}" includes="**">
 -            </zipfileset>
 -        </zip>
 -    </target>
@@ -206,7 +213,7 @@
 +	<target name="welcome-message">
 +		<echo>
 +=======================================================
-+	Compiling GanttProject 2.7
++	Compiling GanttProject 2.8
 +=======================================================
 +		</echo>
 +	</target>
diff --git a/office/ganttproject/ganttproject.SlackBuild b/office/ganttproject/ganttproject.SlackBuild
index fd335eb0cf..45bc85d579 100644
--- a/office/ganttproject/ganttproject.SlackBuild
+++ b/office/ganttproject/ganttproject.SlackBuild
@@ -25,7 +25,7 @@
 # ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 PRGNAM=ganttproject
-VERSION=${VERSION:-2.8.3}
+VERSION=${VERSION:-2.8.4}
 ARCH=noarch
 BUILD=${BUILD:-1}
 TAG=${TAG:-_SBo}
diff --git a/office/ganttproject/ganttproject.info b/office/ganttproject/ganttproject.info
index a95b2ead50..2016100e97 100644
--- a/office/ganttproject/ganttproject.info
+++ b/office/ganttproject/ganttproject.info
@@ -1,8 +1,8 @@
 PRGNAM="ganttproject"
-VERSION="2.8.3"
+VERSION="2.8.4"
 HOMEPAGE="http://www.ganttproject.biz"
-DOWNLOAD="https://github.com/bardsoftware/ganttproject/archive/ganttproject-2.8.3/ganttproject-ganttproject-2.8.3.tar.gz"
-MD5SUM="1ff9c8aae756ba99de4512c0e32474e9"
+DOWNLOAD="https://github.com/bardsoftware/ganttproject/archive/ganttproject-2.8.4/ganttproject-ganttproject-2.8.4.tar.gz"
+MD5SUM="8aa4670dbdcaeae8cb4e2e7e5a74b28c"
 DOWNLOAD_x86_64=""
 MD5SUM_x86_64=""
 REQUIRES="apache-ant jdk"