diff --git a/lib/db/install.xml b/lib/db/install.xml
index 69b53b2f7fb..ddb23c5151e 100644
--- a/lib/db/install.xml
+++ b/lib/db/install.xml
@@ -441,7 +441,7 @@
         <FIELD NAME="mnethostid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="deleted" NEXT="username"/>
         <FIELD NAME="username" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="mnethostid" NEXT="password"/>
         <FIELD NAME="password" TYPE="char" LENGTH="32" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="username" NEXT="idnumber"/>
-        <FIELD NAME="idnumber" TYPE="char" LENGTH="64" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="password" NEXT="firstname"/>
+        <FIELD NAME="idnumber" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="password" NEXT="firstname"/>
         <FIELD NAME="firstname" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="idnumber" NEXT="lastname"/>
         <FIELD NAME="lastname" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="firstname" NEXT="email"/>
         <FIELD NAME="email" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false" ENUM="false" PREVIOUS="lastname" NEXT="emailstop"/>
diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 180678a97fa..8a7f91575bd 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -2966,7 +2966,37 @@ function xmldb_main_upgrade($oldversion=0) {
             }
         }
     }
-        
+
+    if ($result && $oldversion < 2007101512) {
+        notify('Increasing size of user idnumber field, this may take a while...', 'notifysuccess');
+
+    /// Define index idnumber (not unique) to be dropped form user
+        $table = new XMLDBTable('user');
+        $index = new XMLDBIndex('idnumber');
+        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('idnumber'));
+
+    /// Launch drop index idnumber
+        if (index_exists($table, $index)) {
+            $result = $result && drop_index($table, $index);
+        }
+
+    /// Changing precision of field idnumber on table user to (255)
+        $table = new XMLDBTable('user');
+        $field = new XMLDBField('idnumber');
+        $field->setAttributes(XMLDB_TYPE_CHAR, '255', null, XMLDB_NOTNULL, null, null, null, null, 'password');
+
+    /// Launch change of precision for field idnumber
+        $result = $result && change_field_precision($table, $field);
+
+    /// Launch add index idnumber again
+        $index = new XMLDBIndex('idnumber');
+        $index->setAttributes(XMLDB_INDEX_NOTUNIQUE, array('idnumber'));
+        $result = $result && add_index($table, $index);
+
+    /// Main savepoint reached
+        upgrade_main_savepoint($result, 2007101512);
+    }
+
     return $result;
 }
 
diff --git a/version.php b/version.php
index ade53d7c7a3..a31c51ee4d3 100644
--- a/version.php
+++ b/version.php
@@ -6,7 +6,7 @@
 // This is compared against the values stored in the database to determine
 // whether upgrades should be performed (see lib/db/*.php)
 
-    $version = 2007101511;  // YYYYMMDD      = date of the 1.9 branch (don't change)
+    $version = 2007101512;  // YYYYMMDD      = date of the 1.9 branch (don't change)
                             //         X     = release number 1.9.[0,1,2,3...]
                             //          Y.YY = micro-increments between releases