diff --git a/src/Sql/Clause/Join.php b/src/Sql/Clause/Join.php
index 7156423..d62557a 100644
--- a/src/Sql/Clause/Join.php
+++ b/src/Sql/Clause/Join.php
@@ -188,14 +188,14 @@ public function __get(string $name)
             return $this->specification;
         }
         if ('on' === $name) {
+            if ($this->specification instanceof On) {
+                return $this->specification;
+            }
             if ($this->specification === null) {
                 $this->specification = new On();
                 $this->specification->setParent($this);
                 return $this->specification;
             }
-            if ($this->specification instanceof On) {
-                return $this->specification;
-            }
             return null;
         }