diff --git a/debian/changelog b/debian/changelog
index 9950ee3b..166b3a30 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,9 @@
-byobu (4.56) unreleased; urgency=low
+byobu (5.0) unreleased; urgency=low
 
-  * UNRELEASED
+  * etc/byobu/backend, usr/bin/byobu, usr/bin/byobu-config,
+    usr/bin/byobu-select-session, usr/lib/byobu/include/common:
+    - bump up to the 5.x series
+    - change default backend from screen to tmux
 
  -- Dustin Kirkland <kirkland@ubuntu.com>  Sun, 18 Dec 2011 21:35:00 -0600
 
diff --git a/etc/byobu/backend b/etc/byobu/backend
index 34dcce9b..d71e61c5 100644
--- a/etc/byobu/backend
+++ b/etc/byobu/backend
@@ -1,4 +1,4 @@
 # BYOBU_BACKEND can currently be "screen" or "tmux"
 # Override this on a per-user basis by editing "$BYOBU_CONFIG_DIR/backend"
 # or by launching either "byobu-screen" or "byobu-tmux" instead of "byobu".
-BYOBU_BACKEND="screen"
+BYOBU_BACKEND="tmux"
diff --git a/usr/bin/byobu b/usr/bin/byobu
index c96ec1db..53293f54 100755
--- a/usr/bin/byobu
+++ b/usr/bin/byobu
@@ -17,7 +17,7 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-VERSION=4.56
+VERSION=5.0
 PKG="byobu"
 
 # All sorts of things go wrong if you don't own your $HOME dir.
diff --git a/usr/bin/byobu-config b/usr/bin/byobu-config
index b1fdbf2d..9a9bc8a9 100755
--- a/usr/bin/byobu-config
+++ b/usr/bin/byobu-config
@@ -30,7 +30,7 @@ PKG="byobu"
 HOME=os.getenv("HOME")
 USER=os.getenv("USER")
 BYOBU_CONFIG_DIR=os.getenv("BYOBU_CONFIG_DIR", HOME+"/.byobu")
-BYOBU_BACKEND=os.getenv("BYOBU_BACKEND", "screen")
+BYOBU_BACKEND=os.getenv("BYOBU_BACKEND", "tmux")
 BYOBU_SOCKETDIR=os.getenv("SOCKETDIR", "/var/run/screen")
 BYOBU_PREFIX = os.getenv("BYOBU_PREFIX", "/usr")
 SHARE=BYOBU_PREFIX+'/share/'+PKG
diff --git a/usr/bin/byobu-select-session b/usr/bin/byobu-select-session
index 340a2df9..8da8efe2 100755
--- a/usr/bin/byobu-select-session
+++ b/usr/bin/byobu-select-session
@@ -24,7 +24,7 @@ PKG = "byobu"
 SHELL = os.getenv("SHELL", "/bin/bash")
 HOME=os.getenv("HOME")
 BYOBU_CONFIG_DIR=os.getenv("BYOBU_CONFIG_DIR", HOME+"/.byobu")
-BYOBU_BACKEND=os.getenv("BYOBU_BACKEND", "screen")
+BYOBU_BACKEND=os.getenv("BYOBU_BACKEND", "tmux")
 choice = ""
 sessions = []
 text = []
diff --git a/usr/lib/byobu/include/common b/usr/lib/byobu/include/common
index 82e320cb..80ccee8c 100755
--- a/usr/lib/byobu/include/common
+++ b/usr/lib/byobu/include/common
@@ -27,7 +27,7 @@ if [ -z "${BYOBU_INCLUDED_LIBS}" ]; then
 		[ -r "/etc/$PKG/backend" ] && . "/etc/$PKG/backend"
 		[ -r "$BYOBU_CONFIG_DIR/backend" ] && . "$BYOBU_CONFIG_DIR/backend"
 		# Just in case there's no config file at all
-		[ -z "${BYOBU_BACKEND}" ] && BYOBU_BACKEND=screen
+		[ -z "${BYOBU_BACKEND}" ] && BYOBU_BACKEND=tmux
   	fi
 
 	# Creating backend cache