diff --git a/src/View/InitialConditions/Table.py b/src/View/InitialConditions/Table.py
index 0290f817..d3799496 100644
--- a/src/View/InitialConditions/Table.py
+++ b/src/View/InitialConditions/Table.py
@@ -376,9 +376,19 @@ class InitialConditionTableModel(PamhyrTableModel):
         self.layoutChanged.emit()
 
     def generate(self, generator, param, option):
+        self.layoutAboutToBeChanged.emit()
+
+        self._undo.beginMacro(f"generate {generator}")
         self._undo.push(
             GenerateCommand(
                 self._lst, generator, param, option
             )
         )
+        self._undo.push(
+            SortCommand(
+                self._lst, False
+            )
+        )
+        self._undo.endMacro()
+
         self.layoutChanged.emit()
diff --git a/src/View/InitialConditions/UndoCommand.py b/src/View/InitialConditions/UndoCommand.py
index d5af00f5..95f1ee47 100644
--- a/src/View/InitialConditions/UndoCommand.py
+++ b/src/View/InitialConditions/UndoCommand.py
@@ -100,15 +100,19 @@ class SortCommand(QUndoCommand):
         self._indexes = None
 
     def undo(self):
-        ll = self._ics.data
+        order = {
+            id(x): self._indexes[i]
+            for i, x in enumerate(self._ics.data)
+        }
         self._ics.sort(
-            key=lambda x: self._indexes[ll.index(x)]
+            key=lambda x: order.get(id(x), len(order))
         )
 
     def redo(self):
         self._ics.sort(
             reverse=self._reverse,
-            key=lambda x: x["rk"].rk
+            key=lambda x: ((x["rk"] is None),
+                           0.0 if x["rk"] is None else x["rk"].rk)
         )
         if self._indexes is None:
             self._indexes = list(
@@ -182,11 +186,19 @@ class GenerateCommand(QUndoCommand):
         self._ics = ics
         self._param = param
         self._option = option
-        self._copy = self._ics.data
+        # All the rows, with their deleted flag: the generation marks the
+        # previous rows as deleted (clear_data)
+        self._copy = list(self._ics._data)
+        self._deleted = [d.is_deleted() for d in self._copy]
         self._generator = generator
 
     def undo(self):
-        self._ics.data = self._copy
+        for data, deleted in zip(self._copy, self._deleted):
+            if deleted:
+                data.set_as_deleted()
+            else:
+                data.set_as_not_deleted()
+        self._ics.data = list(self._copy)
 
     def redo(self):
         if self._generator == "growing":