diff --git a/test.py b/test.py
index fb2fc64..66b5061 100644
--- a/test.py
+++ b/test.py
@@ -980,7 +980,7 @@ class ParseScreenObstructions:
                         #sprite below them
                         for key in lud:
                             #bmps are stored upside down, so do endswith here..
-                            if key.endswith(tile[-len(tile)*3/4:]):
+                            if key.endswith(tile[int(-len(tile)*3/4):]):
                                 doc = lud.get(key)
                                 break
                         else: