diff --git a/src/wp-includes/cron.php b/src/wp-includes/cron.php
index 244699c8ed..c4ce866cf6 100644
--- a/src/wp-includes/cron.php
+++ b/src/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 );
diff --git a/tests/phpunit/tests/cron.php b/tests/phpunit/tests/cron.php
index 8373d042b9..2d96c2e765 100644
--- a/tests/phpunit/tests/cron.php
+++ b/tests/phpunit/tests/cron.php
@@ -214,20 +214,39 @@ class Tests_Cron extends WP_UnitTestCase {
 	function test_not_duplicate_event() {
 		// duplicate events far apart should work normally
 		$hook = rand_str();
-		$args = array(rand_str());
-		$ts1 = strtotime('+30 minutes');
-		$ts2 = strtotime('+3 minutes');
+		$args = array( rand_str() );
+		$ts1 = strtotime( '+30 minutes' );
+		$ts2 = strtotime( '+3 minutes' );
 
 		// first one works
 		wp_schedule_single_event( $ts1, $hook, $args );
 		// second works too
 		wp_schedule_single_event( $ts2, $hook, $args );
 
-		// the next event should be at +5 minutes, not +3
-		$this->assertEquals( $ts2, wp_next_scheduled($hook, $args) );
+		// the next event should be at +3 minutes, even though that one was scheduled second
+		$this->assertEquals( $ts2, wp_next_scheduled( $hook, $args ) );
 		wp_unschedule_event( $ts2, $hook, $args );
+		// following event at +30 minutes should be there too
+		$this->assertEquals( $ts1, wp_next_scheduled( $hook, $args ) );
+	}
+
+	function test_not_duplicate_event_reversed() {
+		// duplicate events far apart should work normally regardless of order
+		$hook = rand_str();
+		$args = array( rand_str() );
+		$ts1 = strtotime( '+3 minutes' );
+		$ts2 = strtotime( '+30 minutes' );
+
+		// first one works
+		wp_schedule_single_event( $ts1, $hook, $args );
+		// second works too
+		wp_schedule_single_event( $ts2, $hook, $args );
+
+		// the next event should be at +3 minutes
+		$this->assertEquals( $ts1, wp_next_scheduled( $hook, $args ) );
+		wp_unschedule_event( $ts1, $hook, $args );
 		// following event should be there too
-		$this->assertEquals( $ts1, wp_next_scheduled($hook, $args) );
+		$this->assertEquals( $ts2, wp_next_scheduled( $hook, $args ) );
 	}
 }