diff --git a/src/SelectQuery.php b/src/SelectQuery.php
index 86373b7f944e33e35bbaaee4c9557edf011cd298..5ac3a1368c72f26ff0d92dc4e62a9a86ee3f72ae 100644
--- a/src/SelectQuery.php
+++ b/src/SelectQuery.php
@@ -51,6 +51,13 @@ class SelectQuery implements SelectQueryInterface {
    */
   public $offset;
 
+  /**
+   * The operator used to combine conditions, defaults to 'AND'.
+   *
+   * @var string
+   */
+  public $conjunction;
+
   /**
    * SelectQuery constructor.
    *