diff --git a/Civi/Eck/Permissions.php b/Civi/Eck/Permissions.php
index cda90ef..de54935 100644
--- a/Civi/Eck/Permissions.php
+++ b/Civi/Eck/Permissions.php
@@ -103,7 +103,7 @@ public static function getTypePermissionName(string $op, string $type): string {
     if (!in_array($op, [self::ACTION_VIEW, self::ACTION_EDIT, self::ACTION_DELETE], TRUE)) {
       throw new \CRM_Core_Exception("Invalid operation for ECK entity type-specific permission: {$op}.");
     }
-    if (NULL !== \CRM_Eck_BAO_EckEntityType::getEntityType($type)) {
+    if (NULL === \CRM_Eck_BAO_EckEntityType::getEntityType($type)) {
       throw new \CRM_Core_Exception("Invalid ECK entity type name for type-specific permission: {$type}.");
     }
     return "{$op} eck entity {$type}";