diff --git a/src/wp-admin/includes/ajax-actions.php b/src/wp-admin/includes/ajax-actions.php
index 75d7a61000..27ec0d8752 100644
--- a/src/wp-admin/includes/ajax-actions.php
+++ b/src/wp-admin/includes/ajax-actions.php
@@ -3556,9 +3556,9 @@ function wp_ajax_get_revision_diffs() {
 
 	$return = array();
 
-	// Removes the script timeout limit by setting it to 0 allowing ample time for diff UI setup.
 	if ( function_exists( 'set_time_limit' ) ) {
-		set_time_limit( 0 );
+		// Increase the script timeout limit to allow ample time for diff UI setup.
+		set_time_limit( 5 * MINUTE_IN_SECONDS );
 	}
 
 	foreach ( $_REQUEST['compare'] as $compare_key ) {