diff --git a/qemu.hook b/qemu.hook
index 8270f5d..4499676 100755
--- a/qemu.hook
+++ b/qemu.hook
@@ -70,7 +70,7 @@ def prepare_files(domain, env_):
 
         # resize
         cmd = ['/usr/bin/qemu-img',
-               'resize', disk, "+10G"
+               'resize', disk, "+20G"
                ]
         subprocess.call(cmd)