diff --git a/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.xml b/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.xml
index 899c0bc0a3..1d2c40b78c 100644
--- a/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.xml
+++ b/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.xml
@@ -198,6 +198,11 @@
 	      <entry>Kernel source files</entry>
 	    </row>
 
+	    <row>
+	      <entry><filename>tests/</filename></entry>
+	      <entry>The &os; test suite</entry>
+	    </row>
+
 	    <row>
 	      <entry><filename>tools/</filename></entry>
 	      <entry>Tools used for maintenance and testing of