diff --git a/astroid/nodes/node_ng.py b/astroid/nodes/node_ng.py
index 3a482f3cc..5ef347df5 100644
--- a/astroid/nodes/node_ng.py
+++ b/astroid/nodes/node_ng.py
@@ -326,17 +326,18 @@ def scope(self) -> nodes.LocalsDictNodeNG:
             raise ParentMissingError(target=self)
         return self.parent.scope()
 
-    def root(self) -> nodes.Module:
+    def root(self) -> nodes.Module | None:
         """Return the root node of the syntax tree.
 
-        :returns: The root node.
+        :returns: The root node. Might be None, if the node has been
+            created ad-hoc, e.g. with nodes.const_factory
         """
         if not (parent := self.parent):
-            return self  # type: ignore[return-value] # Only 'Module' does not have a parent node.
+            return self if isinstance(self, nodes.Module) else None
 
         while parent.parent:
             parent = parent.parent
-        return parent  # type: ignore[return-value] # Only 'Module' does not have a parent node.
+        return parent if isinstance(parent, nodes.Module) else None
 
     def child_sequence(self, child):
         """Search for the sequence that contains this child.