diff --git a/pyanaconda/modules/storage/devicetree/model.py b/pyanaconda/modules/storage/devicetree/model.py
index 084622080ca..258c6c2b378 100644
--- a/pyanaconda/modules/storage/devicetree/model.py
+++ b/pyanaconda/modules/storage/devicetree/model.py
@@ -285,6 +285,7 @@ def _mark_protected_devices(self):
         identify protected devices.
         """
         protected = []
+        protected_with_ancestors = []
 
         # Resolve the protected device specs to devices.
         for spec in self.protected_devices:
@@ -306,7 +307,7 @@ def _mark_protected_devices(self):
 
         if live_device:
             log.debug("Resolved live device to %s.", live_device.name)
-            protected.append(live_device)
+            protected_with_ancestors.append(live_device)
 
         # Find the backing device of a stage2 source and its parents.
         source_device = find_backing_device(self.devicetree, DRACUT_REPO_DIR)
@@ -319,16 +320,20 @@ def _mark_protected_devices(self):
         # storage disks as ignored so they are protected from teardown.
         # Here we protect also cdrom devices from tearing down that, in case of
         # cdroms, involves unmounting which is undesirable (see bug #1671713).
-        protected.extend(dev for dev in self.devicetree.devices if dev.type == "cdrom")
+        protected_with_ancestors.extend(dev for dev in self.devicetree.devices
+                                        if dev.type == "cdrom")
 
         # Protect also all devices with an iso9660 file system. It will protect
         # NVDIMM devices that can be used only as an installation source anyway
         # (see the bug #1856264).
-        protected.extend(dev for dev in self.devicetree.devices if dev.format.type == "iso9660")
+        protected_with_ancestors.extend(dev for dev in self.devicetree.devices
+                                        if dev.format.type == "iso9660")
 
         # Mark the collected devices as protected.
         for dev in protected:
             self._mark_protected_device(dev)
+        for dev in protected_with_ancestors:
+            self._mark_protected_device(dev, include_ancestors=True)
 
     def protect_devices(self, protected_names):
         """Protect given devices.
@@ -353,23 +358,31 @@ def protect_devices(self, protected_names):
         # Update the list.
         self.protected_devices = protected_names
 
-    def _mark_protected_device(self, device):
+    def _mark_protected_device(self, device, include_ancestors=False):
         """Mark a device and its ancestors as protected."""
         if not device:
             return
 
-        for d in device.ancestors:
-            log.debug("Marking device %s as protected.", d.name)
-            d.protected = True
+        device.protected = True
+        log.debug("Marking device %s as protected.", device.name)
+        if include_ancestors:
+            for d in device.ancestors:
+                log.debug("Marking ancestor %s of device %s as protected.",
+                          d.name, device.name)
+                d.protected = True
 
-    def _mark_unprotected_device(self, device):
+    def _mark_unprotected_device(self, device, include_ancestors=False):
         """Mark a device and its ancestors as unprotected."""
         if not device:
             return
 
-        for d in device.ancestors:
-            log.debug("Marking device %s as unprotected.", d.name)
-            d.protected = False
+        device.protected = False
+        log.debug("Marking device %s as unprotected.", device.name)
+        if include_ancestors:
+            for d in device.ancestors:
+                log.debug("Marking ancestor %s of device %s as unprotected.",
+                          d.name, device.name)
+                d.protected = False
 
     @property
     def usable_disks(self):