diff --git a/qubes/ext/gui.py b/qubes/ext/gui.py
index 9d46d1cc..c68b7402 100644
--- a/qubes/ext/gui.py
+++ b/qubes/ext/gui.py
@@ -30,7 +30,7 @@ import qubes.ext
 
 
 # "LVDS connected 1024x768+0+0 (normal left inverted right) 304mm x 228mm"
-REGEX_OUTPUT = re.compile(r'''
+REGEX_OUTPUT = re.compile(rb'''
         (?x)                           # ignore whitespace
         ^                              # start of string
         (?P<output>[A-Za-z0-9\-]*)[ ]  # LVDS VGA etc
@@ -58,7 +58,7 @@ def get_monitor_layout():
 
     for line in subprocess.Popen(
             ['xrandr', '-q'], stdout=subprocess.PIPE).stdout:
-        if not line.startswith("Screen") and not line.startswith(" "):
+        if not line.startswith(b"Screen") and not line.startswith(b" "):
             output_params = REGEX_OUTPUT.match(line).groupdict()
             if output_params['width']:
                 phys_size = ""
@@ -109,9 +109,9 @@ class GUI(qubes.ext.Extension):
             # get owner of X11 session
             session_owner = None
             for line in subprocess.check_output(['xhost']).splitlines():
-                if line == 'SI:localuser:root':
+                if line == b'SI:localuser:root':
                     pass
-                elif line.startswith('SI:localuser:'):
+                elif line.startswith(b'SI:localuser:'):
                     session_owner = line.split(":")[2]
             if session_owner is not None:
                 data_dir = os.path.expanduser(
@@ -277,7 +277,7 @@ class GUI(qubes.ext.Extension):
         pipe = vm.run('QUBESRPC qubes.SetMonitorLayout dom0',
             passio_popen=True, wait=True)
 
-        pipe.stdin.write(''.join(layout))
+        pipe.stdin.write(''.join(layout).encode())
         pipe.stdin.close()
         pipe.wait()
 
diff --git a/qubes/storage/__init__.py b/qubes/storage/__init__.py
index 0bbb52a3..da57401b 100644
--- a/qubes/storage/__init__.py
+++ b/qubes/storage/__init__.py
@@ -327,7 +327,7 @@ class Storage(object):
             volume = self.vm.volumes[volume]
         self.get_pool(volume).resize(volume, size)
         if self.vm.is_running():
-            self.vm.run_service('qubes.ResizeDisk', input=volume.name,
+            self.vm.run_service('qubes.ResizeDisk', input=volume.name.encode(),
                 user='root', wait=True)
 
     def create(self):
diff --git a/qubes/vm/qubesvm.py b/qubes/vm/qubesvm.py
index 7acb65b8..abf16597 100644
--- a/qubes/vm/qubesvm.py
+++ b/qubes/vm/qubesvm.py
@@ -1203,7 +1203,7 @@ class QubesVM(qubes.vm.mix.net.NetVMMixin, qubes.vm.BaseVM):
         # Note : User root is redefined to SYSTEM in the Windows agent code
         p = self.run('QUBESRPC qubes.WaitForSession none',
             user="root", passio_popen=True, gui=False, wait=True)
-        p.communicate(input=self.default_user)
+        p.communicate(input=self.default_user.encode())
 
     def create_on_disk(self, pool=None, pools=None):
         '''Create files needed for VM.