diff --git a/tests/phpunit/tests/date/getFeedBuildDate.php b/tests/phpunit/tests/date/getFeedBuildDate.php
index 455bfa0b80..afe5bbd1fa 100644
--- a/tests/phpunit/tests/date/getFeedBuildDate.php
+++ b/tests/phpunit/tests/date/getFeedBuildDate.php
@@ -61,9 +61,10 @@ class Tests_Date_Get_Feed_Build_Date extends WP_UnitTestCase {
 		);
 
 		$this->assertEquals(
-			$datetime_utc->format( DATE_RFC3339 ),
-			get_feed_build_date( DATE_RFC3339 ),
-			'Fall back to time of last post modified with no posts'
+			strtotime( $datetime_utc->format( DATE_RFC3339 ) ),
+			strtotime( get_feed_build_date( DATE_RFC3339 ) ),
+			'Fall back to time of last post modified with no posts',
+			2
 		);
 
 		$post_id_broken = $this->factory->post->create();
@@ -74,9 +75,10 @@ class Tests_Date_Get_Feed_Build_Date extends WP_UnitTestCase {
 		$wp_query->posts = array( $post_broken );
 
 		$this->assertEquals(
-			$datetime_utc->format( DATE_RFC3339 ),
-			get_feed_build_date( DATE_RFC3339 ),
-			'Fall back to time of last post modified with broken post object'
+			strtotime( $datetime_utc->format( DATE_RFC3339 ) ),
+			strtotime( get_feed_build_date( DATE_RFC3339 ) ),
+			'Fall back to time of last post modified with broken post object',
+			2
 		);
 	}
 }