diff --git a/build_library/disk_util b/build_library/disk_util
index b59710e43d..6f51e3989e 100755
--- a/build_library/disk_util
+++ b/build_library/disk_util
@@ -162,6 +162,7 @@ def LoadPartitionConfig(options):
     # metadata. Kinda odd but the best place I've got with this data structure.
     if layout_name == options.disk_layout:
       metadata['blocks'] = disk_block_count
+      metadata['bytes'] = disk_block_count * metadata['block_size']
 
 
   # Verify 'base' before other layouts because it is inherited by the others
@@ -267,13 +268,18 @@ def WritePartitionTable(options, config=None, partitions=None):
   if not (config and partitions):
     config, partitions = LoadPartitionConfig(options)
 
-  # If we are not creating a fresh image all partitions must be compatible.
-  if not options.create:
+  if options.create:
+    Cgpt('create', '-c', '-s', config['metadata']['blocks'], options.disk_image)
+  else:
+    # If we are not creating a fresh image all partitions must be compatible.
     GetPartitionTableFromImage(options, config, partitions)
     if not all(p['image_compat'] for p in partitions.itervalues()):
       raise InvalidLayout("New disk layout is incompatible existing image")
 
-  Cgpt('create', '-c', '-s', config['metadata']['blocks'], options.disk_image)
+    # Extend the disk image size as needed
+    with open(options.disk_image, 'r+') as image_fd:
+      image_fd.truncate(config['metadata']['bytes'])
+    Cgpt('repair', options.disk_image)
 
   syslinux = None
   for partition in partitions.itervalues():