diff --git a/book/binary/chapter.tex b/book/binary/chapter.tex
index b0c67b4..f0a062e 100644
--- a/book/binary/chapter.tex
+++ b/book/binary/chapter.tex
@@ -859,7 +859,7 @@ When adding {\em signed} numbers, an overflow only occurs when the two
 addends are positive and sum is negative or the addends are both negative 
 and the sum is positive.  
 
-When subtracting {\em unsigned}, an overflow only occurs when the
+When subtracting {\em signed} numbers, an overflow only occurs when the
 minuend is positive and the subtrahend is negative and difference is negative
 or when the minuend is negative and the subtrahend is positive and the 
 difference is positive.%