diff --git a/devel/devel.module b/devel/devel.module
index 7865022..2b62e93 100644
--- a/devel/devel.module
+++ b/devel/devel.module
@@ -52,10 +52,14 @@ function devel_entity_type_alter(array &$entity_types) {
   /** @var $entity_types \Drupal\Core\Entity\EntityTypeInterface[] */
   foreach ($entity_types as $entity_type_id => $entity_type) {
     if ($entity_type->hasViewBuilderClass() && $entity_type->hasLinkTemplate('canonical')) {
-      $entity_type->setLinkTemplate('devel-render', $entity_type->getLinkTemplate('canonical') . '/devel/render');
+      $link_template = $entity_type->getLinkTemplate('canonical');
+      $link_template = ($link_template[0] !== '/') ? '/' . $link_template : $link_template;
+      $entity_type->setLinkTemplate('devel-render', $link_template . '/devel/render');
     }
     if ($entity_type->hasFormClasses() && $entity_type->hasLinkTemplate('edit-form')) {
-      $entity_type->setLinkTemplate('devel-load', $entity_type->getLinkTemplate('edit-form') . '/devel');
+      $link_template = $entity_type->getLinkTemplate('edit-form');
+      $link_template = ($link_template[0] !== '/') ? '/' . $link_template : $link_template;
+      $entity_type->setLinkTemplate('devel-load', $link_template . '/devel');
     }
   }
 }