diff --git a/source/BUG/strings.py b/source/BUG/strings.py
index 5cdfb0f..628089e 100644
--- a/source/BUG/strings.py
+++ b/source/BUG/strings.py
@@ -114,7 +114,7 @@ def substring_after(s: str, sub: str) -> str:
     """
     BUG035: substring_after should return the substring after the first occurrence of sub, not before it.
     """
-    result = s.split(sub)[0]
+    result = s.split(sub)[1]
     return result