diff --git a/system/database/drivers/odbc/odbc_result.php b/system/database/drivers/odbc/odbc_result.php
index a81a2b8..5d64a46 100644
--- a/system/database/drivers/odbc/odbc_result.php
+++ b/system/database/drivers/odbc/odbc_result.php
@@ -188,7 +188,7 @@
 	 */
 	function _odbc_fetch_object(& $odbc_result) {
 		$rs = array();
-		$rs_obj = false;
+		$rs_obj = FALSE;
 		if (odbc_fetch_into($odbc_result, $rs)) {
 			foreach ($rs as $k=>$v) {
 				$field_name= odbc_field_name($odbc_result, $k+1);
@@ -210,7 +210,7 @@
 	 */
 	function _odbc_fetch_array(& $odbc_result) {
 		$rs = array();
-		$rs_assoc = false;
+		$rs_assoc = FALSE;
 		if (odbc_fetch_into($odbc_result, $rs)) {
 			$rs_assoc=array();
 			foreach ($rs as $k=>$v) {
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 0bb7974..81ca6e0 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -330,21 +330,21 @@
 		$v = $this->_version();
 		$v = $v['server'];
 
-		$table	= func_num_args() > 0 ? func_get_arg(0) : null;
-		$column	= func_num_args() > 1 ? func_get_arg(1) : null;
+		$table	= func_num_args() > 0 ? func_get_arg(0) : NULL;
+		$column	= func_num_args() > 1 ? func_get_arg(1) : NULL;
 
-		if ($table == null && $v >= '8.1')
+		if ($table == NULL && $v >= '8.1')
 		{
 			$sql='SELECT LASTVAL() as ins_id';
 		}
-		elseif ($table != null && $column != null && $v >= '8.0')
+		elseif ($table != NULL && $column != NULL && $v >= '8.0')
 		{
 			$sql = sprintf("SELECT pg_get_serial_sequence('%s','%s') as seq", $table, $column);
 			$query = $this->query($sql);
 			$row = $query->row();
 			$sql = sprintf("SELECT CURRVAL('%s') as ins_id", $row->seq);
 		}
-		elseif ($table != null)
+		elseif ($table != NULL)
 		{
 			// seq_name passed in table parameter
 			$sql = sprintf("SELECT CURRVAL('%s') as ins_id", $table);
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 745fb7c..c6d7c29 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1177,7 +1177,7 @@
 	{
 		if ( ! is_numeric($str))
 		{
-			return false;
+			return FALSE;
 		}
 		return $str > $min;
 	}
@@ -1195,7 +1195,7 @@
 	{
 		if ( ! is_numeric($str))
 		{
-			return false;
+			return FALSE;
 		}
 		return $str < $max;
 	}
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 41f9ad3..8902f52 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -749,7 +749,7 @@
 
 		@chmod($this->full_dst_path, FILE_WRITE_MODE);
 
-		return true;
+		return TRUE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index 9cf307c..0d5a261 100644
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -358,7 +358,7 @@
 	var $errno			= '';
 	var $errstring		= '';
 	var $timeout		= 5;
-	var $no_multicall	= false;
+	var $no_multicall	= FALSE;
 
 	public function __construct($path, $server, $port=80)
 	{
@@ -896,7 +896,7 @@
 				$this->xh[$the_parser]['isf'] = 1;
 			break;
 			case 'PARAM':
-				$this->xh[$the_parser]['value'] = null;
+				$this->xh[$the_parser]['value'] = NULL;
 			break;
 			case 'VALUE':
 				$this->xh[$the_parser]['vt'] = 'value';
@@ -925,7 +925,7 @@
 				$this->xh[$the_parser]['valuestack'][0]['name'] = '';
 
 				// Set NULL value to check to see if value passed for this param/member
-				$this->xh[$the_parser]['value'] = null;
+				$this->xh[$the_parser]['value'] = NULL;
 			break;
 			case 'DATA':
 			case 'METHODCALL':