diff --git a/subiquity/common/filesystem/actions.py b/subiquity/common/filesystem/actions.py
index 572348db..33b2e792 100644
--- a/subiquity/common/filesystem/actions.py
+++ b/subiquity/common/filesystem/actions.py
@@ -292,7 +292,7 @@ def _can_delete_partition(partition):
     if partition.device._has_preexisting_partition():
         return _("Cannot delete a single partition from a device that "
                  "already has partitions.")
-    if partition.is_bootloader_partition:
+    if boot.is_bootloader_partition(partition):
         return _("Cannot delete required bootloader partition")
     return _can_delete_generic(partition)
 
diff --git a/subiquity/common/filesystem/boot.py b/subiquity/common/filesystem/boot.py
index 1c155493..6479a9d7 100644
--- a/subiquity/common/filesystem/boot.py
+++ b/subiquity/common/filesystem/boot.py
@@ -96,3 +96,14 @@ def _is_esp_partition(partition):
 def all_boot_devices(model):
     """Return all current boot devices for `model`."""
     return [disk for disk in model.all_disks() if is_boot_device(disk)]
+
+
+def is_bootloader_partition(partition):
+    if partition._m.bootloader == Bootloader.BIOS:
+        return partition.flag == "bios_grub"
+    elif partition._m.bootloader == Bootloader.UEFI:
+        return is_esp(partition)
+    elif partition._m.bootloader == Bootloader.PREP:
+        return partition.flag == "prep"
+    else:
+        return False
diff --git a/subiquity/common/filesystem/manipulator.py b/subiquity/common/filesystem/manipulator.py
index d538927a..e24a7166 100644
--- a/subiquity/common/filesystem/manipulator.py
+++ b/subiquity/common/filesystem/manipulator.py
@@ -296,7 +296,7 @@ class FilesystemManipulator:
             boot_disk.grub_device = False
         partitions = [
             p for p in boot_disk.partitions()
-            if p.is_bootloader_partition
+            if boot.is_bootloader_partition(p)
             ]
         remount = False
         if boot_disk.preserve:
diff --git a/subiquity/models/filesystem.py b/subiquity/models/filesystem.py
index 2b78beb2..8c31fb31 100644
--- a/subiquity/models/filesystem.py
+++ b/subiquity/models/filesystem.py
@@ -677,21 +677,10 @@ class Partition(_Formattable):
     def _path(self):
         return partition_kname(self.device.path, self._number)
 
-    @property
-    def is_bootloader_partition(self):
-        from subiquity.common.filesystem import boot
-        if self._m.bootloader == Bootloader.BIOS:
-            return self.flag == "bios_grub"
-        elif self._m.bootloader == Bootloader.UEFI:
-            return boot.is_esp(self)
-        elif self._m.bootloader == Bootloader.PREP:
-            return self.flag == "prep"
-        else:
-            return False
-
     @property
     def ok_for_raid(self):
-        if self.is_bootloader_partition:
+        from subiquity.common.filesystem import boot
+        if boot.is_bootloader_partition(self):
             return False
         if self._fs is not None:
             if self._fs.preserve:
@@ -1303,6 +1292,7 @@ class FilesystemModel(object):
 
     def add_partition(self, device, size, flag="", wipe=None,
                       grub_device=None):
+        from subiquity.common.filesystem import boot
         if size > device.free_for_partitions:
             raise Exception("%s > %s", size, device.free_for_partitions)
         real_size = align_up(size)
@@ -1312,7 +1302,7 @@ class FilesystemModel(object):
         p = Partition(
             m=self, device=device, size=real_size, flag=flag, wipe=wipe,
             grub_device=grub_device)
-        if p.is_bootloader_partition:
+        if boot.is_bootloader_partition(p):
             device._partitions.insert(0, device._partitions.pop())
         device.ptable = device.ptable_for_new_partition()
         dasd = device.dasd()