diff --git a/examples/roman2.py b/examples/roman2.py
index 50dee99..8589ed9 100644
--- a/examples/roman2.py
+++ b/examples/roman2.py
@@ -24,7 +24,7 @@ roman_numeral_map = (('M',  1000),
 def to_roman(n):
     '''convert integer to Roman numeral'''
     if n > 3999:
-        raise OutOfRangeError('number out of range (must be less than 3999)')
+        raise OutOfRangeError('number out of range (must be less than 4000)')
 
     result = ''
     for numeral, integer in roman_numeral_map:
diff --git a/unit-testing.html b/unit-testing.html
index 9a91c05..3109530 100755
--- a/unit-testing.html
+++ b/unit-testing.html
@@ -319,7 +319,7 @@ FAILED (failures=1)</samp></pre>
 <pre class=pp><code>def to_roman(n):
     '''convert integer to Roman numeral'''
     if n > 3999:
-<a>        raise OutOfRangeError('number out of range (must be less than 3999)')  <span class=u>&#x2460;</span></a>
+<a>        raise OutOfRangeError('number out of range (must be less than 4000)')  <span class=u>&#x2460;</span></a>
 
     result = ''
     for numeral, integer in roman_numeral_map: