diff --git a/phpBB/includes/search/fulltext_mysql.php b/phpBB/includes/search/fulltext_mysql.php
index 2084864e4d..700b8695dc 100644
--- a/phpBB/includes/search/fulltext_mysql.php
+++ b/phpBB/includes/search/fulltext_mysql.php
@@ -56,21 +56,21 @@ class phpbb_search_fulltext_mysql extends phpbb_search_base
 	 * Associative array stores the min and max word length to be searched
 	 * @var array
 	 */
-	public $word_length = array();
+	protected $word_length = array();
 
 	/**
 	 * Contains tidied search query.
 	 * Operators are prefixed in search query and common words excluded
 	 * @var string
 	 */
-	public $search_query;
+	protected $search_query;
 
 	/**
 	 * Contains common words.
 	 * Common words are words with length less/more than min/max length
 	 * @var array
 	 */
-	public $common_words = array();
+	protected $common_words = array();
 
 	/**
 	 * Constructor
diff --git a/phpBB/includes/search/fulltext_native.php b/phpBB/includes/search/fulltext_native.php
index 14d4c60134..e25b1fe11d 100644
--- a/phpBB/includes/search/fulltext_native.php
+++ b/phpBB/includes/search/fulltext_native.php
@@ -32,21 +32,21 @@ class phpbb_search_fulltext_native extends phpbb_search_base
 	 * Associative array stores the min and max word length to be searched
 	 * @var array
 	 */
-	public $word_length = array();
+	protected $word_length = array();
 
 	/**
 	 * Contains tidied search query.
 	 * Operators are prefixed in search query and common words excluded
 	 * @var string
 	 */
-	public $search_query;
+	protected $search_query;
 
 	/**
 	 * Contains common words.
 	 * Common words are words with length less/more than min/max length
 	 * @var array
 	 */
-	public $common_words = array();
+	protected $common_words = array();
 
 	/**
 	 * Post ids of posts containing words that are to be included
diff --git a/phpBB/includes/search/fulltext_postgres.php b/phpBB/includes/search/fulltext_postgres.php
index 98bf010c93..12a1203249 100644
--- a/phpBB/includes/search/fulltext_postgres.php
+++ b/phpBB/includes/search/fulltext_postgres.php
@@ -82,20 +82,20 @@ class phpbb_search_fulltext_postgres extends phpbb_search_base
 	 * Operators are prefixed in search query and common words excluded
 	 * @var string
 	 */
-	public $search_query;
+	protected $search_query;
 
 	/**
 	 * Contains common words.
 	 * Common words are words with length less/more than min/max length
 	 * @var array
 	 */
-	public $common_words = array();
+	protected $common_words = array();
 
 	/**
 	 * Associative array stores the min and max word length to be searched
 	 * @var array
 	 */
-	public $word_length = array();
+	protected $word_length = array();
 
 	/**
 	 * Constructor
diff --git a/phpBB/includes/search/fulltext_sphinx.php b/phpBB/includes/search/fulltext_sphinx.php
index 37e9240c7b..674029fe6c 100644
--- a/phpBB/includes/search/fulltext_sphinx.php
+++ b/phpBB/includes/search/fulltext_sphinx.php
@@ -118,7 +118,7 @@ class phpbb_search_fulltext_sphinx
 	 * Operators are prefixed in search query and common words excluded
 	 * @var string
 	 */
-	public $search_query;
+	protected $search_query;
 
 	/**
 	 * Constructor