diff --git a/ricecooker/classes/nodes.py b/ricecooker/classes/nodes.py
index <HASH>..<HASH> 100644
--- a/ricecooker/classes/nodes.py
+++ b/ricecooker/classes/nodes.py
@@ -59,6 +59,8 @@ class Node(object):
             Args: file_to_add (File): file model to add to node
             Returns: None
         """
+        from .files import File
+        assert isinstance(file_to_add, File), "Files being added must be instances of a subclass of File class"
         file_to_add.node = self
         self.files.append(file_to_add)
Add additional check to ensure files being added are subclasses of File