Index: bp-forums/bp-forums-functions.php
--- bp-forums/bp-forums-functions.php
+++ bp-forums/bp-forums-functions.php
@@ -352,24 +352,19 @@
  * @param int $user_id The user id
  */
 function bp_forums_reply_exists( $text = '', $topic_id = 0, $user_id = 0 ) {
-	global $wpdb;
 
-	$reply_exists = false;
-
 	if ( $text && $topic_id && $user_id ) {
 		do_action( 'bbpress_init' );
 
-		$args = array(
+		$query = new BB_Query( 'post', array(
 			'post_author_id' => $user_id,
-			'topic_id'       => $topic_id
-		);
+			'topic_id'       => $topic_id,
+			'post_text'      => $text
+		) );
 
-		// BB_Query's post_text parameter does a MATCH, while we need exact matches
-		add_filter( 'get_posts_where', create_function( '$q', 'return $q . " AND p.post_text = \'' . $wpdb->escape( $text ) . '\'";' ) );
-
-		$query = new BB_Query( 'post', $args );
-
 		$reply_exists = !empty( $query->results );
+	} else {
+		$reply_exists = false;
 	}
 
 	return apply_filters( 'bp_forums_reply_exists', $reply_exists, $text, $topic_id, $user_id );