diff --git a/Doc/ext/ext.tex b/Doc/ext/ext.tex
index d8a3d59..787914e 100644
--- a/Doc/ext/ext.tex
+++ b/Doc/ext/ext.tex
@@ -134,7 +134,7 @@
 conventionally named \var{self} and \var{args}.
 
 The \var{self} argument is only used when the \C{} function implements a
-builtin method.  This will be discussed later. In the example,
+built-in method.  This will be discussed later. In the example,
 \var{self} will always be a \NULL{} pointer, since we are defining
 a function, not a method.  (This is done so that the interpreter
 doesn't have to understand two different types of \C{} functions.)