diff --git a/lslopt/lsloptimizer.py b/lslopt/lsloptimizer.py
index 851cbda..cb025f9 100644
--- a/lslopt/lsloptimizer.py
+++ b/lslopt/lsloptimizer.py
@@ -566,7 +566,7 @@ class optimizer(object):
         """
 
         if 'optimize' not in options:
-            return
+            return treesymtab
 
         self.foldtabs = 'foldtabs' in options