diff --git a/subiquity/models/filesystem.py b/subiquity/models/filesystem.py
index baf655e3..0b11cba9 100644
--- a/subiquity/models/filesystem.py
+++ b/subiquity/models/filesystem.py
@@ -673,6 +673,7 @@ class Partition(_Formattable):
     multipath = attr.ib(default=None)
     offset = attr.ib(default=None)
     resize = attr.ib(default=None)
+    partition_type = attr.ib(default=None)
 
     def available(self):
         if self.flag in ['bios_grub', 'prep'] or self.grub_device: