diff --git a/mod/hotpot/db/mysql.php b/mod/hotpot/db/mysql.php
index 23fe22d6c40..746d3e37aa1 100644
--- a/mod/hotpot/db/mysql.php
+++ b/mod/hotpot/db/mysql.php
@@ -27,32 +27,14 @@ function hotpot_upgrade($oldversion) {
 		$ok = $ok && hotpot_update_to_v2_1_16();
 	}
 
-
-    if ($oldversion < 2006042600) {
-        table_column('hotpot_attempts','starttime','starttime','int','10','unsigned','0','not null');
-        table_column('hotpot_attempts','endtime','endtime','int','10','unsigned','0','not null');
-        table_column('hotpot_attempts','score','score','int','6','unsigned','0','not null');
-        table_column('hotpot_attempts','penalties','penalties','int','6','unsigned','0','not null');
-        table_column('hotpot_attempts','timestart','timestart','int','10','unsigned','0','not null');
-        table_column('hotpot_attempts','timefinish','timefinish','int','10','unsigned','0','not null');
-        table_column('hotpot_attempts','clickreportid','clickreportid','int','10','unsigned','0','not null');
-        
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_questions CHANGE type type tinyint(4) unsigned NOT NULL default '0'");
-
-        table_column('hotpot_questions','text','text','int','10','unsigned','0','not null');
-        
-        
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_responses CHANGE weighting weighting smallint(8) unsigned NOT NULL default '0'");
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_responses CHANGE score score smallint(8) unsigned NOT NULL default '0'");
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_responses CHANGE hints hints smallint(6) unsigned NOT NULL default '0'");
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_responses CHANGE clues clues smallint(6) unsigned NOT NULL default '0'");
-        execute_sql("ALTER TABLE {$CFG->prefix}hotpot_responses CHANGE checks checks smallint(6) unsigned NOT NULL default '0'");
-
-    }
+	// update to HotPot v2.1.17
+	if ($oldversion < 2006042601) {
+		$ok = $ok && hotpot_get_update_to_v2();
+		$ok = $ok && hotpot_update_to_v2_1_17();
+	}
 	
 	return $ok;
 }
-
 function hotpot_get_update_to_v2() {
 	global $CFG;
 	$filepath = "$CFG->dirroot/mod/hotpot/db/update_to_v2.php";
diff --git a/mod/hotpot/db/update_to_v2.php b/mod/hotpot/db/update_to_v2.php
index c337548e29a..f0eb1ced3a0 100644
--- a/mod/hotpot/db/update_to_v2.php
+++ b/mod/hotpot/db/update_to_v2.php
@@ -1,4 +1,36 @@
 <?PHP
+function hotpot_update_to_v2_1_17() {
+	global $CFG;
+	$ok = true;
+
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'starttime', '10');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'endtime', '10');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'score', '6');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'penalties',  '6');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'timestart', '10');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'timefinish', '10');
+	$ok = $ok && hotpot_denull_int_field('hotpot_attempts', 'clickreportid', '10');
+
+	$ok = $ok && hotpot_denull_int_field('hotpot_questions', 'type', '4');
+	$ok = $ok && hotpot_denull_int_field('hotpot_questions', 'text', '10');
+
+	$ok = $ok && hotpot_denull_int_field('hotpot_responses', 'weighting', '8');
+	$ok = $ok && hotpot_denull_int_field('hotpot_responses', 'score', '8');
+	$ok = $ok && hotpot_denull_int_field('hotpot_responses', 'hints', '6');
+	$ok = $ok && hotpot_denull_int_field('hotpot_responses', 'clues', '6');
+	$ok = $ok && hotpot_denull_int_field('hotpot_responses', 'checks', '6');
+
+	return $ok;
+}
+function hotpot_denull_int_field($table, $field, $size) {
+	global $CFG;
+	$ok = true;
+
+	$ok = $ok && execute_sql("UPDATE {$CFG->prefix}$table SET $field=0 WHERE $field IS NULL");
+	$ok = $ok && hotpot_db_update_field_type($table, $field, $field, 'INTEGER', $size, 'UNSIGNED', 'NOT NULL', 0);
+
+	return $ok;
+}
 function hotpot_update_to_v2_1_16() {
 	global $CFG;
 	$ok = true;
diff --git a/mod/hotpot/version.php b/mod/hotpot/version.php
index dd2f8610187..bb1814f2ace 100644
--- a/mod/hotpot/version.php
+++ b/mod/hotpot/version.php
@@ -3,7 +3,7 @@
 ///  Code fragment to define the version of hotpot
 ///  This fragment is called by moodle_needs_upgrading() and /admin/index.php
 /////////////////////////////////////////////////////////////////////////////////
-$module->version  = 2006042600;  // release date of this version (see note below)
+$module->version  = 2006042601;  // release date of this version (see note below)
 $module->release  = 'v2.1.16';    // human-friendly version name (used in mod/hotpot/lib.php)
 $module->cron     = 0;           // period for cron to check this module (secs)
 // interpretation of YYYYMMDDXY version numbers