diff --git a/tests/php/test-amp-gallery-embed-handler.php b/tests/php/test-amp-gallery-embed-handler.php
index 3a685e1eb0f..1990c24ff87 100644
--- a/tests/php/test-amp-gallery-embed-handler.php
+++ b/tests/php/test-amp-gallery-embed-handler.php
@@ -280,7 +280,7 @@ public function test__conversion( $source, $expected, $use_legacy_mode = false )
 		$content = str_replace( 'jpg.webp', '.jpg', $content );
 
 		// Remove lazy loading attribute.
-		$content = str_replace( 'loading="lazy" ', '', $content );
+		$content = preg_replace( '/\s+loading="lazy"/', '', $content );
 
 		$this->assertEquals(
 			$this->normalize( $expected ),