diff --git a/mod/hotpot/db/install.xml b/mod/hotpot/db/install.xml
index 76bea300dfa..89089f3ab91 100644
--- a/mod/hotpot/db/install.xml
+++ b/mod/hotpot/db/install.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="mod/hotpot/db" VERSION="20060811" COMMENT="XMLDB file for Moodle mod/hotpot">
+<XMLDB PATH="mod/hotpot/db" VERSION="20060901" COMMENT="XMLDB file for Moodle mod/hotpot"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="../../../lib/xmldb/xmldb.xsd"
+>
   <TABLES>
     <TABLE NAME="hotpot" COMMENT="details about Hot Potatoes quizzes" NEXT="hotpot_attempts">
       <FIELDS>
@@ -71,12 +74,16 @@
         <FIELD NAME="name" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="id" NEXT="type"/>
         <FIELD NAME="type" TYPE="int" LENGTH="4" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="name" NEXT="text"/>
         <FIELD NAME="text" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="type" NEXT="hotpot"/>
-        <FIELD NAME="hotpot" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="text"/>
+        <FIELD NAME="hotpot" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="text" NEXT="md5key"/>
+        <FIELD NAME="md5key" TYPE="char" LENGTH="32" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="hotpot"/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for hotpot_questions" NEXT="hotpot"/>
         <KEY NAME="hotpot" TYPE="foreign" FIELDS="hotpot" REFTABLE="hotpot" REFFIELDS="id" PREVIOUS="primary"/>
       </KEYS>
+      <INDEXES>
+        <INDEX NAME="md5key" UNIQUE="false" FIELDS="md5key"/>
+      </INDEXES>
     </TABLE>
     <TABLE NAME="hotpot_responses" COMMENT="details about responses in Hot Potatoes quiz attempts" PREVIOUS="hotpot_questions" NEXT="hotpot_strings">
       <FIELDS>
@@ -101,11 +108,15 @@
     <TABLE NAME="hotpot_strings" COMMENT="strings used in Hot Potatoes questions and responses" PREVIOUS="hotpot_responses">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="true" ENUM="false" NEXT="string"/>
-        <FIELD NAME="string" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="id"/>
+        <FIELD NAME="string" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="id" NEXT="md5key"/>
+        <FIELD NAME="md5key" TYPE="char" LENGTH="32" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="string"/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for hotpot_strings"/>
       </KEYS>
+      <INDEXES>
+        <INDEX NAME="md5key" UNIQUE="false" FIELDS="md5key"/>
+      </INDEXES>
     </TABLE>
   </TABLES>
-</XMLDB>
+</XMLDB>
\ No newline at end of file