diff --git a/include/dblayer/sqlite.php b/include/dblayer/sqlite.php
index e4c86ad71..bbd3c2be3 100644
--- a/include/dblayer/sqlite.php
+++ b/include/dblayer/sqlite.php
@@ -456,9 +456,9 @@ function add_field($table_name, $field_name, $field_type, $allow_null, $default_
 
 		if (!$allow_null)
 			$query .= ' NOT NULL';
-		
-		if ($default_value === '')
-			$default_value = '\'\'';
+
+		if (is_string($default_value))
+			$default_value = '\''.$this->escape($default_value).'\'';
 
 		if (!is_null($default_value))
 			$query .= ' DEFAULT '.$default_value;