diff --git a/wp-includes/cron.php b/wp-includes/cron.php
index 244699c8ed..c4ce866cf6 100644
--- a/wp-includes/cron.php
+++ b/wp-includes/cron.php
@@ -20,10 +20,11 @@
  * @param array $args Optional. Arguments to pass to the hook's callback function.
  */
 function wp_schedule_single_event( $timestamp, $hook, $args = array()) {
-	// don't schedule a duplicate if there's already an identical event due in the next 10 minutes
+	// don't schedule a duplicate if there's already an identical event due within 10 minutes of it
 	$next = wp_next_scheduled($hook, $args);
-	if ( $next && $next <= $timestamp + 10 * MINUTE_IN_SECONDS )
+	if ( $next && abs( $next - $timestamp ) <= 10 * MINUTE_IN_SECONDS ) {
 		return;
+	}
 
 	$crons = _get_cron_array();
 	$event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => false, 'args' => $args );