diff --git a/LDP/howto/docbook/NIS-HOWTO.sgml b/LDP/howto/docbook/NIS-HOWTO.sgml
index c64e37a0..0b4d9e39 100644
--- a/LDP/howto/docbook/NIS-HOWTO.sgml
+++ b/LDP/howto/docbook/NIS-HOWTO.sgml
@@ -604,7 +604,8 @@ configuration file !
 
 </Sect1>
 
-<Sect1 id="setting_NIS">
+<!-- openjade forbids underscore in id="" attribute; thus setting-NIS -->
+<Sect1 id="setting-NIS">
 <Title>What do you need to set up NIS?
 <IndexTerm><Primary
 >NIS!setting up</Primary></IndexTerm>
@@ -710,7 +711,8 @@ and glibc 2.1 or later.
 </Sect2>
 </Sect1>
 
-<Sect1 id="settingup_client">
+<!-- openjade forbids underscore in id="" attribute; thus settingup-client -->
+<Sect1 id="settingup-client">
 <Title>Setting Up the NIS Client
 </Title>
 <Sect2>