diff --git a/doc/manual/background.tex b/doc/manual/background.tex
index 046545b1..715590a5 100644
--- a/doc/manual/background.tex
+++ b/doc/manual/background.tex
@@ -124,7 +124,7 @@ Python version at the time of this writing, generators are enabled by
 default.
 
 Besides generators, Python~2.3 has several other interesting new
-features, and it runs 25--35\% faster than Python~2.2. For this
+features, and it runs 25--35\% faster than Python~2.2. For these
 reasons, I recommend MyHDL users to upgrade to Python~2.3. The next
 major release of MyHDL will rely on on the new features and will
 require Python~2.3 or higher.