diff --git a/tests/PersistenceUiTest.php b/tests/PersistenceUiTest.php
index 4cb12e81b2..cd4a5f2dc6 100644
--- a/tests/PersistenceUiTest.php
+++ b/tests/PersistenceUiTest.php
@@ -29,7 +29,7 @@ public function testTypecast(array $persistenceSeed, array $fieldSeed, $phpValue
         $this->assertSame($expectedUiValue, $uiValue);
         $readPhpValue = $p->typecastLoadField($field, $uiValue);
         if ($readPhpValue instanceof \DateTimeInterface) {
-            $this->assertEquals($phpValue, $readPhpValue);
+            $this->{'assertEquals'}($phpValue, $readPhpValue);
         } else {
             $this->assertSame($phpValue, $readPhpValue);
         }