diff --git a/installer/portable/update-filebot.sh b/installer/portable/update-filebot.sh
index 865ea443..14398975 100644
--- a/installer/portable/update-filebot.sh
+++ b/installer/portable/update-filebot.sh
@@ -23,32 +23,35 @@ cd "$WORKING_DIR"
 
 
 # update core application files
-JAR_FILE="$APP_ROOT/FileBot.jar"
-JAR_URL="https://sourceforge.net/projects/filebot/files/filebot/HEAD/FileBot.jar"
+JAR_XZ_FILE="$APP_ROOT/FileBot.jar.xz"
+JAR_XZ_URL="https://sourceforge.net/projects/filebot/files/filebot/HEAD/FileBot.jar.xz"
 
 # check if file has changed
-JAR_SHA1_EXPECTED=`curl --retry 5 "$JAR_URL/list" | egrep -o "[a-z0-9]{40}"`
-JAR_SHA1=`sha1sum $JAR_FILE | cut -d' ' -f1`
+JAR_XZ_SHA1_EXPECTED=`curl --retry 5 "$JAR_XZ_URL/list" | egrep -o "[a-z0-9]{40}"`
+JAR_XZ_SHA1=`sha1sum $JAR_XZ_FILE | cut -d' ' -f1`
 
-if [ -z "$JAR_SHA1_EXPECTED" ]; then
+if [ -z "$JAR_XZ_SHA1_EXPECTED" ]; then
 	echo "SHA1 hash unknown"
 	exit 1
 fi
 
-if [ "$JAR_SHA1" == "$JAR_SHA1_EXPECTED" ]; then
-	echo "$JAR_FILE [SHA1: $JAR_SHA1]"
+if [ "$JAR_XZ_SHA1" == "$JAR_XZ_SHA1_EXPECTED" ]; then
+	echo "$JAR_XZ_FILE [SHA1: $JAR_XZ_SHA1]"
 	exit 0
 fi
 
-echo "Update $JAR_FILE"
-curl -L -o "$JAR_FILE" -z "$JAR_FILE" --retry 5 "$JAR_URL"	# FRS will redirect to (unsecure) HTTP download link
+echo "Update $JAR_XZ_FILE"
+curl -L -o "$JAR_XZ_FILE" -z "$JAR_XZ_FILE" --retry 5 "$JAR_XZ_URL"	# FRS will redirect to (unsecure) HTTP download link
 
-# check if file has been corrupted
-JAR_SHA1=`sha1sum $JAR_FILE | cut -d' ' -f1`
-echo "$JAR_FILE [SHA1: $JAR_SHA1]"
+# check if file has been corrupted (or modified) in transit
+JAR_XZ_SHA1=`sha1sum $JAR_XZ_FILE | cut -d' ' -f1`
+echo "$JAR_XZ_FILE [SHA1: $JAR_XZ_SHA1]"
 
-if [ "$JAR_SHA1" != "$JAR_SHA1_EXPECTED" ]; then
-	echo "SHA1 hash mismatch [SHA1: $JAR_SHA1_EXPECTED]"
-	rm -vf "$JAR_FILE"
+if [ "$JAR_XZ_SHA1" != "$JAR_XZ_SHA1_EXPECTED" ]; then
+	echo "SHA1 hash mismatch [SHA1: $JAR_XZ_SHA1_EXPECTED]"
+	rm -vf "$JAR_XZ_FILE"
 	exit 1
 fi
+
+# unpack new jar
+xz --decompress --force --keep "$JAR_XZ_FILE"