diff --git a/Doc/Sda1/prerequisites.xml b/Doc/Sda1/prerequisites.xml
index afc8f8e31cd7736fdd6692365af19aa309f0ead4..afecdf794788dd439ed81e915753cc241377bdfd 100644
--- a/Doc/Sda1/prerequisites.xml
+++ b/Doc/Sda1/prerequisites.xml
@@ -11,7 +11,7 @@
          xmlns:db="http://docbook.org/ns/docbook">
   <title>Prerequisites</title>
 
-  <figure xml:id="sd1_fig_examCheatSheet">
+  <figure xml:id="sda1_fig_examCheatSheet">
     <title>Personal examination cheat sheets</title>
 
     <itemizedlist>