diff --git a/ch02/stump.py b/ch02/stump.py
index 841ce983..5037338f 100644
--- a/ch02/stump.py
+++ b/ch02/stump.py
@@ -19,6 +19,8 @@
 
 
 best_acc = -1.0
+best_fi = -1.0
+best_t = -1.0
 for fi in range(features.shape[1]):
     thresh = features[:, fi].copy()
     thresh.sort()