Index: core/kernel/db/db_connection.php
===================================================================
--- core/kernel/db/db_connection.php
+++ core/kernel/db/db_connection.php
@@ -63,10 +63,9 @@
 		/**
 		 * Function to handle sql errors
 		 *
-		 * @var Array|string
-		 * @access public
+		 * @var callable
 		 */
-		public $errorHandler = '';
+		protected $errorHandler = '';
 
 		/**
 		 * Error code
@@ -161,10 +160,10 @@
 			$this->serverIndex = $server_index;
 
 			if ( !$error_handler ) {
-				$this->errorHandler = Array(&$this, 'handleError');
+				$this->setErrorHandler(array(&$this, 'handleError'));
 			}
 			else {
-				$this->errorHandler = $error_handler;
+				$this->setErrorHandler($error_handler);
 			}
 
 			$this->_captureStatistics = defined('DBG_CAPTURE_STATISTICS') && DBG_CAPTURE_STATISTICS && !(defined('ADMIN') && ADMIN);
@@ -910,6 +909,19 @@
 
 			return false;
 		}
+
+		/**
+		 * Sets an error handler.
+		 *
+		 * @param callable $error_handler Error handler.
+		 *
+		 * @return void
+		 */
+		public function setErrorHandler(callable $error_handler)
+		{
+			$this->errorHandler = $error_handler;
+		}
+
 	}
 
 
Index: core/kernel/db/db_load_balancer.php
===================================================================
--- core/kernel/db/db_load_balancer.php
+++ core/kernel/db/db_load_balancer.php
@@ -27,10 +27,9 @@
 	/**
 	 * Function to handle sql errors
 	 *
-	 * @var string
-	 * @access public
+	 * @var callable
 	 */
-	public $errorHandler = '';
+	protected $errorHandler = '';
 
 	/**
 	 * Database connection settings
@@ -59,8 +58,7 @@
 	/**
 	 * Connection references to opened connections
 	 *
-	 * @var Array
-	 * @access protected
+	 * @var IDBConnection[]
 	 */
 	protected $connections = Array ();
 
@@ -123,7 +121,7 @@
 		parent::__construct();
 
 		$this->dbType = $db_type;
-		$this->errorHandler = $error_handler;
+		$this->setErrorHandler($error_handler);
 
 		$this->DBClusterTimeout *= 1e6; // convert to milliseconds
 	}
@@ -867,4 +865,21 @@
 
 		return $conn->getSlaveLag();
 	}
+
+	/**
+	 * Sets an error handler.
+	 *
+	 * @param callable $error_handler Error handler.
+	 *
+	 * @return void
+	 */
+	public function setErrorHandler(callable $error_handler)
+	{
+		$this->errorHandler = $error_handler;
+
+		foreach ( $this->connections as $connection ) {
+			$connection->setErrorHandler($error_handler);
+		}
+	}
+
 }
Index: core/kernel/db/i_db_connection.php
===================================================================
--- core/kernel/db/i_db_connection.php
+++ core/kernel/db/i_db_connection.php
@@ -259,4 +259,14 @@
 		 * @access public
 		 */
 		public function getSlaveLag();
+
+		/**
+		 * Sets an error handler.
+		 *
+		 * @param callable $error_handler Error handler.
+		 *
+		 * @return void
+		 */
+		public function setErrorHandler(callable $error_handler);
+
 	}
Index: core/units/helpers/deployment_helper.php
===================================================================
--- core/units/helpers/deployment_helper.php
+++ core/units/helpers/deployment_helper.php
@@ -377,7 +377,7 @@
 	private function upgradeDatabase()
 	{
 		$this->loadAppliedRevisions();
-		$this->Conn->errorHandler = Array (&$this, 'handleSqlError');
+		$this->Conn->setErrorHandler(array(&$this, 'handleSqlError'));
 
 		$this->out('Verifying Database Revisions ... ');