diff --git a/mod/assignment/db/install.xml b/mod/assignment/db/install.xml
index 68515329c64..d19fd6f2b85 100644
--- a/mod/assignment/db/install.xml
+++ b/mod/assignment/db/install.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="mod/assignment/db" VERSION="20060921" COMMENT="XMLDB file for Moodle mod/assignment"
+<XMLDB PATH="mod/assignment/db" VERSION="20070919" COMMENT="XMLDB file for Moodle mod/assignment"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="../../../lib/xmldb/xmldb.xsd"
 >
@@ -41,8 +41,8 @@
         <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="userid" NEXT="timemodified"/>
         <FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="timecreated" NEXT="numfiles"/>
         <FIELD NAME="numfiles" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="timemodified" NEXT="data1"/>
-        <FIELD NAME="data1" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="numfiles" NEXT="data2"/>
-        <FIELD NAME="data2" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="data1" NEXT="grade"/>
+        <FIELD NAME="data1" TYPE="text" LENGTH="small" NOTNULL="false" SEQUENCE="false" ENUM="false" PREVIOUS="numfiles" NEXT="data2"/>
+        <FIELD NAME="data2" TYPE="text" LENGTH="small" NOTNULL="false" SEQUENCE="false" ENUM="false" PREVIOUS="data1" NEXT="grade"/>
         <FIELD NAME="grade" TYPE="int" LENGTH="11" NOTNULL="true" UNSIGNED="false" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="data2" NEXT="submissioncomment"/>
         <FIELD NAME="submissioncomment" TYPE="text" LENGTH="small" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="grade" NEXT="format"/>
         <FIELD NAME="format" TYPE="int" LENGTH="4" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="submissioncomment" NEXT="teacher"/>
diff --git a/mod/assignment/db/upgrade.php b/mod/assignment/db/upgrade.php
index 63c1f7a8aa6..a5b8101213a 100644
--- a/mod/assignment/db/upgrade.php
+++ b/mod/assignment/db/upgrade.php
@@ -31,6 +31,24 @@ function xmldb_assignment_upgrade($oldversion=0) {
         $db->debug = true;
     }
 
+    if ($result && $oldversion < 2007091900) { /// MDL-11268
+
+    /// Changing nullability of field data1 on table assignment_submissions to null
+        $table = new XMLDBTable('assignment_submissions');
+        $field = new XMLDBField('data1');
+        $field->setAttributes(XMLDB_TYPE_TEXT, 'small', null, null, null, null, null, null, 'numfiles');
+
+    /// Launch change of nullability for field data1
+        $result = $result && change_field_notnull($table, $field);
+
+    /// Changing nullability of field data2 on table assignment_submissions to null
+        $field = new XMLDBField('data2');
+        $field->setAttributes(XMLDB_TYPE_TEXT, 'small', null, null, null, null, null, null, 'data1');
+
+    /// Launch change of nullability for field data2
+        $result = $result && change_field_notnull($table, $field);
+    }
+
     return $result;
 }
 
diff --git a/mod/assignment/version.php b/mod/assignment/version.php
index 0ac76a128f8..e601648738c 100644
--- a/mod/assignment/version.php
+++ b/mod/assignment/version.php
@@ -5,7 +5,7 @@
 //  This fragment is called by /admin/index.php
 ////////////////////////////////////////////////////////////////////////////////
 
-$module->version  = 2007090100;
+$module->version  = 2007091900;
 $module->requires = 2007083101;  // Requires this Moodle version
 $module->cron     = 60;