diff --git a/docs/swi.tex b/docs/swi.tex
index 8b62940e5..c35d5e561 100644
--- a/docs/swi.tex
+++ b/docs/swi.tex
@@ -307,7 +307,7 @@ present.
 @snindex attr_unify_hook/2
 @cnindex attr_unify_hook/2
 Hook that must be defined in the module an attributed variable refers
-to. Is is called @emph{after} the attributed variable has been
+to. It is called @emph{after} the attributed variable has been
 unified with a non-var term, possibly another attributed variable.
 @var{AttValue} is the attribute that was associated to the variable
 in this module and @var{VarValue} is the new value of the variable.