diff --git a/include/v8-debug.h b/include/v8-debug.h
index 0d0ee73..e41df29 100644
--- a/include/v8-debug.h
+++ b/include/v8-debug.h
@@ -18,13 +18,11 @@
   Exception = 2,
   NewFunction = 3,
   BeforeCompile = 4,
-  AfterCompile  = 5,
+  AfterCompile = 5,
   CompileError = 6,
-  PromiseEvent = 7,
-  AsyncTaskEvent = 8,
+  AsyncTaskEvent = 7,
 };
 
-
 class V8_EXPORT Debug {
  public:
   /**
@@ -276,6 +274,14 @@
    */
   static MaybeLocal<Array> GetInternalProperties(Isolate* isolate,
                                                  Local<Value> value);
+
+  /**
+   * Defines if the ES2015 tail call elimination feature is enabled or not.
+   * The change of this flag triggers deoptimization of all functions that
+   * contain calls at tail position.
+   */
+  static bool IsTailCallEliminationEnabled(Isolate* isolate);
+  static void SetTailCallEliminationEnabled(Isolate* isolate, bool enabled);
 };