diff --git a/blivetgui/dialogs/size_chooser.py b/blivetgui/dialogs/size_chooser.py
index 53cf46b8..b41aa563 100644
--- a/blivetgui/dialogs/size_chooser.py
+++ b/blivetgui/dialogs/size_chooser.py
@@ -65,7 +65,7 @@ class SizeArea(GUIWidget):
     name = "size area"
     glade_file = "size_area.ui"
 
-    def __init__(self, device_type, parents, min_limit, max_limit, raid_type):
+    def __init__(self, device_type, parents, min_limit, max_limit, raid_type, overprovisioning=False):
         """
             :param device_type: type of device we are creating
             :param parents: list of available/selected parents
@@ -89,6 +89,7 @@ def __init__(self, device_type, parents, min_limit, max_limit, raid_type):
 
         self._min_size_limit = min_limit
         self._max_size_limit = max_limit
+        self._overprovisioning = overprovisioning
 
         # "main" size chooser
         self.main_chooser = SizeChooser(max_size=self.max_size, min_size=self.min_size)
@@ -157,7 +158,10 @@ def max_size(self):
             parents, raid level and limits for the newly created device
         """
         if self._parent_area is None:
-            return min(sum(parent.max_size for parent in self.parents), self.max_size_limit)
+            if self._overprovisioning:
+                return self.max_size_limit
+            else:
+                return min(sum(parent.max_size for parent in self.parents), self.max_size_limit)
         else:
             return self._parent_area.total_max
 
@@ -223,10 +227,18 @@ def get_selection(self):
             them (either specified by user or just fraction of total size)
         """
         if self._parent_area is None:
-            # no advanced selection -> we will use all available parents and set
-            # same size for each of them and return total selected size
             total_size = self.main_chooser.selected_size
-            parents = self._get_parents_allocation()
+
+            if self._overprovisioning:
+                # with overprovisioning parent allocation doesn't really make sense
+                parents = [ParentSelection(parent_device=p.device,
+                                           free_space=size.Size(0),
+                                           selected_size=total_size) for p in self.parents]
+            else:
+                # no advanced selection -> we will use all available parents and set
+                # same size for each of them and return total selected size
+                parents = self._get_parents_allocation()
+
             return SizeSelection(total_size=total_size, parents=parents)
         else:
             # selection is handled by the parent area
diff --git a/tests/blivetgui_tests/size_widgets_test.py b/tests/blivetgui_tests/size_widgets_test.py
index 6306f24a..837ac464 100644
--- a/tests/blivetgui_tests/size_widgets_test.py
+++ b/tests/blivetgui_tests/size_widgets_test.py
@@ -573,6 +573,28 @@ def test_70_parent_allocation(self):
         selected_sizes = [r.selected_size for r in ret]
         self.assertListEqual(selected_sizes, [Size(1), Size(2)])
 
+    def test_75_parent_allocation_overprovisioning(self):
+        """ Test allocating size on parents without ParentArea with overprovisioning """
+
+        # -- same size parents
+        parents = [MagicMock(device=self._mock_device(), min_size=Size("1 MiB"), max_size=Size("1 GiB"),
+                             reserved_size=Size(0)),
+                   MagicMock(device=self._mock_device(), min_size=Size("1 MiB"), max_size=Size("1 GiB"),
+                             reserved_size=Size(0))]
+
+        size_area = SizeArea(device_type="lvm", parents=parents,
+                             min_limit=Size(1), max_limit=Size("200 GiB"),
+                             raid_type=None, overprovisioning=True)
+
+        # select maximum (bigger than parents) --> both parents should have max_limit selected
+        size_area.main_chooser.selected_size = Size("200 GiB")
+        ret = size_area.get_selection()
+        self.assertEqual(len(ret.parents), 2)
+        self.assertEqual(ret.parents[0].parent_device, parents[0].device)
+        self.assertEqual(ret.parents[0].selected_size, Size("200 GiB"))
+        self.assertEqual(ret.parents[1].parent_device, parents[1].device)
+        self.assertEqual(ret.parents[1].selected_size, Size("200 GiB"))
+
 
 @unittest.skipUnless("DISPLAY" in os.environ.keys(), "requires X server")
 class ParentAreaTest(unittest.TestCase):