Index: src/includes/common/ajax.php
===================================================================
--- src/includes/common/ajax.php	(revision 7009)
+++ src/includes/common/ajax.php	(working copy)
@@ -114,8 +114,10 @@
 function bbp_ajax_headers() {
 
 	// Set the header content type
-	@header( 'Content-Type: ' . get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' ) );
-	@header( 'X-Robots-Tag: noindex' );
+	if ( ! headers_sent() ) {
+		header( 'Content-Type: ' . get_option( 'html_type' ) . '; charset=' . get_option( 'blog_charset' ) );
+		header( 'X-Robots-Tag: noindex' );
+	}
 
 	// Disable content sniffing in browsers that support it
 	send_nosniff_header();
@@ -153,7 +155,9 @@
 	}
 
 	// Send back the JSON
-	@header( 'Content-type: application/json' );
+	if ( ! headers_sent() ) {
+		header( 'Content-type: application/json' );
+	}
 	echo json_encode( $response );
 	die();
 }