diff --git a/Doc/Sda1/mongodb.xml b/Doc/Sda1/mongodb.xml
index ecce6a86733e426d30e959fee5bc97f3949dc3ef..b3064833a8b0d4214d3bdbb3b892e435493708aa 100644
--- a/Doc/Sda1/mongodb.xml
+++ b/Doc/Sda1/mongodb.xml
@@ -9,7 +9,7 @@
          xmlns:db="http://docbook.org/ns/docbook">
   <title><productname>MongoDB</productname></title>
 
-  <section xml:id="sd1SectMongodbPrerequisite">
+  <section xml:id="sda1SectMongodbPrerequisite">
     <title>Prerequisites</title>
 
     <para><xref linkend="glo_Ubuntu"/> installation instructions are on offer