diff --git a/core/lib/Drupal/Core/Url.php b/core/lib/Drupal/Core/Url.php
index 859cf07..b5685cf 100644
--- a/core/lib/Drupal/Core/Url.php
+++ b/core/lib/Drupal/Core/Url.php
@@ -643,7 +643,14 @@ public function toString() {
    * {@inheritdoc}
    */
   public function __toString() {
-    return $this->toString();
+    try {
+      return $this->toString();
+    }
+    catch (\Exception $e) {
+      // PHP does not allow an exception to be thrown from within __toString()
+      // so make sure we suppress them all.
+      return '';
+    }
   }
 
   /**