diff --git a/tests/test_chinese.py b/tests/test_chinese.py
index 83e2d70..4bde6c2 100644
--- a/tests/test_chinese.py
+++ b/tests/test_chinese.py
@@ -1,4 +1,4 @@
-from wordfreq import tokenize, word_frequency
+from wordfreq import tokenize, word_frequency, zipf_frequency
 import pytest
 
 
@@ -80,8 +80,10 @@ def test_alternate_codes():
 
 
 def test_unreasonably_long():
-    # This crashed earlier versions of wordfreq
+    # This crashed earlier versions of wordfreq due to an overflow in
+    # exponentiation. We've now changed the sequence of operations so it
+    # will underflow instead.
     lots_of_ls = 'l' * 800
-    assert word_frequency(lots_of_ls, 'zh') < 1e-300
+    assert word_frequency(lots_of_ls, 'zh') == 0.
     assert zipf_frequency(lots_of_ls, 'zh') == 0.