diff --git a/src/FeedIo/Filter/ModifiedSince.php b/src/FeedIo/Filter/ModifiedSince.php
index 6b49b8c5..7a44c4d7 100644
--- a/src/FeedIo/Filter/ModifiedSince.php
+++ b/src/FeedIo/Filter/ModifiedSince.php
@@ -40,6 +40,6 @@ public function isValid(ItemInterface $item) : bool
             return $item->getLastModified() > $this->date;
         }
 
-        return false;
+        return true;
     }
 }
diff --git a/tests/FeedIo/Filter/ModifiedSinceTest.php b/tests/FeedIo/Filter/ModifiedSinceTest.php
index 99ffc150..050182f2 100644
--- a/tests/FeedIo/Filter/ModifiedSinceTest.php
+++ b/tests/FeedIo/Filter/ModifiedSinceTest.php
@@ -45,6 +45,6 @@ public function testIsTooOld()
     public function testIsNotValid()
     {
         $item = new Item();
-        $this->assertFalse($this->object->isValid($item));
+        $this->assertTrue($this->object->isValid($item));
     }
 }