diff --git a/bootstrapvz/providers/azure/tasks/boot.py b/bootstrapvz/providers/azure/tasks/boot.py
index 3112b8e..c93b85a 100644
--- a/bootstrapvz/providers/azure/tasks/boot.py
+++ b/bootstrapvz/providers/azure/tasks/boot.py
@@ -23,11 +23,13 @@ class PatchUdev(Task):
 class ConfigureGrub(Task):
 	description = 'Change grub configuration to allow for ttyS0 output'
 	phase = phases.system_modification
+	predecessors = [grub.ConfigureGrub]
 	successors = [grub.InstallGrub_1_99, grub.InstallGrub_2]
 
 	@classmethod
 	def run(cls, info):
 		from bootstrapvz.common.tools import sed_i
 		grub_config = os.path.join(info.root, 'etc/default/grub')
+		sed_i(grub_config, r'^(GRUB_CMDLINE_LINUX_DEFAULT=.*)', r'GRUB_CMDLINE_LINUX_DEFAULT=""')
 		sed_i(grub_config, r'^(GRUB_CMDLINE_LINUX*=".*)"\s*$', r'\1console=tty0 console=ttyS0,115200n8 earlyprintk=ttyS0,115200 rootdelay=300"')
 		sed_i(grub_config, r'^.*(GRUB_TIMEOUT=).*$', r'GRUB_TIMEOUT=5')