diff --git a/lib/db/install.xml b/lib/db/install.xml
index 98800d60752..05d99f8e6dd 100644
--- a/lib/db/install.xml
+++ b/lib/db/install.xml
@@ -1351,7 +1351,7 @@
         <FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="false" COMMENT="The id of the question being attempted. Foreign key references question.id." PREVIOUS="behaviour" NEXT="variant"/>
         <FIELD NAME="variant" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="false" DEFAULT="1" COMMENT="The variant of the qusetion being used." PREVIOUS="questionid" NEXT="maxmark"/>
         <FIELD NAME="maxmark" TYPE="number" LENGTH="12" NOTNULL="true" UNSIGNED="false" SEQUENCE="false" DECIMALS="7" COMMENT="The grade this question is marked out of in this attempt." PREVIOUS="variant" NEXT="minfraction"/>
-        <FIELD NAME="minfraction" TYPE="number" LENGTH="12" NOTNULL="true" UNSIGNED="true" SEQUENCE="false" DECIMALS="7" COMMENT="Some questions can award negative marks. This indicates the most negative mark that can be awarded, on the faction scale where the maximum positive mark is 1." PREVIOUS="maxmark" NEXT="flagged"/>
+        <FIELD NAME="minfraction" TYPE="number" LENGTH="12" NOTNULL="true" UNSIGNED="false" SEQUENCE="false" DECIMALS="7" COMMENT="Some questions can award negative marks. This indicates the most negative mark that can be awarded, on the faction scale where the maximum positive mark is 1." PREVIOUS="maxmark" NEXT="flagged"/>
         <FIELD NAME="flagged" TYPE="int" LENGTH="1" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" COMMENT="Whether this question has been flagged within the attempt." PREVIOUS="minfraction" NEXT="questionsummary"/>
         <FIELD NAME="questionsummary" TYPE="text" LENGTH="small" NOTNULL="false" SEQUENCE="false" COMMENT="If this question uses randomisation, it should set this field to summarise what random version the student actually saw. This is a human-readable textual summary of the student's response which might, for example, be used in a report." PREVIOUS="flagged" NEXT="rightanswer"/>
         <FIELD NAME="rightanswer" TYPE="text" LENGTH="small" NOTNULL="false" SEQUENCE="false" COMMENT="This is a human-readable textual summary of the right answer to this question. Might be used, for example on the quiz preview, to help people who are testing the question. Or might be used in reports." PREVIOUS="questionsummary" NEXT="responsesummary"/>
diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 9f68acdf39b..a8bd913e2ac 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -6545,6 +6545,19 @@ WHERE gradeitemid IS NOT NULL AND grademax IS NOT NULL");
         upgrade_main_savepoint(true, 2011060800.01);
     }
 
+    if ($oldversion < 2011062000.01) {
+        // Changing sign of field minfraction on table question_attempts to signed
+        $table = new xmldb_table('question_attempts');
+        $field = new xmldb_field('minfraction', XMLDB_TYPE_NUMBER, '12, 7', null,
+                XMLDB_NOTNULL, null, null, 'maxmark');
+
+        // Launch change of sign for field minfraction
+        $dbman->change_field_unsigned($table, $field);
+
+        // Main savepoint reached
+        upgrade_main_savepoint(true, 2011062000.01);
+    }
+
     return true;
 }
 
diff --git a/version.php b/version.php
index 15bc3637afd..f51b5d2e9bc 100644
--- a/version.php
+++ b/version.php
@@ -31,7 +31,7 @@ defined('MOODLE_INTERNAL') || die();
 
 
 
-$version  = 2011062000.00;              // YYYYMMDD      = weekly release date of this DEV branch
+$version  = 2011062000.01;              // YYYYMMDD      = weekly release date of this DEV branch
                                         //         RR    = release increments - 00 in DEV branches
                                         //           .XX = incremental changes