diff -u b/core/modules/breakpoint/src/Entity/BreakpointGroup.php b/core/modules/breakpoint/src/Entity/BreakpointGroup.php
--- b/core/modules/breakpoint/src/Entity/BreakpointGroup.php
+++ b/core/modules/breakpoint/src/Entity/BreakpointGroup.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\breakpoint\Entity;
 
-use Drupal\breakpoint\InvalidBreakpointNameException;
 use Drupal\Core\Config\Entity\ConfigEntityBase;
 use Drupal\breakpoint\BreakpointGroupInterface;
 use Drupal\breakpoint\BreakpointInterface;