diff --git a/usr/lib/byobu/include/select-session.py b/usr/lib/byobu/include/select-session.py
index 0fb28c9f..4a22b64b 100755
--- a/usr/lib/byobu/include/select-session.py
+++ b/usr/lib/byobu/include/select-session.py
@@ -86,6 +86,33 @@ def get_sessions():
 	return sessions
 
 
+def cull_zombies(session_name):
+	# When using tmux session groups, closing a client will leave
+	# unattached "zombie" sessions that will never be reattached.
+	# Search for and kill any unattached hidden sessions in the same group
+	if BYOBU_BACKEND == "tmux":
+		output = subprocess.Popen(["tmux", "list-sessions"], stdout=subprocess.PIPE).communicate()[0]
+		if sys.stdout.encoding is None:
+			output = output.decode("UTF-8")
+		else:
+			output = output.decode(sys.stdout.encoding)
+		if not output:
+			return
+
+		# Find the master session to extract the group number. We use
+		# the group number to be extra sure the right session is getting
+		# killed. We don't want to accidentally kill the wrong one
+		pattern = "^%s:.+\\((group \\d+)\\).*$" % session_name
+		master = re.search(pattern, output, re.MULTILINE)
+		if not master:
+			return
+
+		# Kill all the matching hidden & unattached sessions
+		pattern = "^_%s-\\d+:.+\\(%s\\)$" % (session_name, master.group(1))
+		for s in re.findall(pattern, output, re.MULTILINE):
+			subprocess.Popen(["tmux", "kill-session", "-t", s.split(":")[0]])
+
+
 def update_environment(session):
 	backend, session_name = session.split("____", 2)
 	for var in BYOBU_UPDATE_ENVVARS:
@@ -101,11 +128,12 @@ def update_environment(session):
 def attach_session(session):
 	update_environment(session)
 	backend, session_name = session.split("____", 2)
+	cull_zombies(session_name)
 	# must use the binary, not the wrapper!
 	if backend == "tmux":
-		os.execvp("tmux", ["", "-2", "attach", "-t", session_name])
+		os.execvp("tmux", ["tmux", "-2", "new-session", "-t", session_name, "-s", "_%s-%i" % (session_name, os.getpid())])
 	else:
-		os.execvp("screen", ["", "-AOxRR", session_name])
+		os.execvp("screen", ["screen", "-AOxRR", session_name])
 
 sessions = get_sessions()
 
@@ -153,9 +181,9 @@ if choice >= 1:
 	if sessions[choice - 1] == "NEW":
 		# Create a new session
 		if BYOBU_BACKEND == "tmux":
-			os.execvp("byobu", ["", "new-session", SHELL])
+			os.execvp("byobu", ["byobu", "new-session", SHELL])
 		else:
-			os.execvp("byobu", ["", SHELL])
+			os.execvp("byobu", ["byobu", SHELL])
 	elif sessions[choice - 1] == "SHELL":
 		os.execvp(SHELL, [SHELL])
 	else:
@@ -167,4 +195,4 @@ if BYOBU_BACKEND == "tmux":
 	args = ""
 else:
 	args = "-AOxRR"
-os.execvp("byobu", ["", args])
+os.execvp("byobu", ["byobu", args])