diff --git a/stubs/EntityManager.stub b/stubs/EntityManager.stub
index 6dc13e1c..32452dbb 100644
--- a/stubs/EntityManager.stub
+++ b/stubs/EntityManager.stub
@@ -70,4 +70,9 @@ class EntityManager implements EntityManagerInterface
      */
     public function flush($entity = null);
 
+	/**
+	 * @return bool
+	 * @phpstan-impure
+	 */
+	public function isOpen();
 }
diff --git a/stubs/EntityManagerDecorator.stub b/stubs/EntityManagerDecorator.stub
index 670d2e8a..eecd7a58 100644
--- a/stubs/EntityManagerDecorator.stub
+++ b/stubs/EntityManagerDecorator.stub
@@ -61,4 +61,9 @@ class EntityManagerDecorator implements EntityManagerInterface
 	 */
 	public function copy($entity, $deep = false);
 
+	/**
+	 * @return bool
+	 * @phpstan-impure
+	 */
+	public function isOpen();
 }
diff --git a/stubs/EntityManagerInterface.stub b/stubs/EntityManagerInterface.stub
index 5625f33c..5fd8024a 100644
--- a/stubs/EntityManagerInterface.stub
+++ b/stubs/EntityManagerInterface.stub
@@ -78,4 +78,9 @@ interface EntityManagerInterface extends ObjectManager
 	 */
 	public function wrapInTransaction(callable $func);
 
+	/**
+	 * @return bool
+	 * @phpstan-impure
+	 */
+	public function isOpen();
 }