diff --git a/reference/classobj/functions/is-subclass-of.xml b/reference/classobj/functions/is-subclass-of.xml
index 37479aec03..f8789f81fa 100644
--- a/reference/classobj/functions/is-subclass-of.xml
+++ b/reference/classobj/functions/is-subclass-of.xml
@@ -80,7 +80,7 @@
        <entry>5.3.7</entry>
        <entry>
         Added support for <parameter>class_name</parameter> to work with
-        intrefaces 
+        interfaces 
        </entry>
       </row>
       <row>