diff --git a/index.d.ts b/index.d.ts
index b879be2..0ec7441 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -60,6 +60,10 @@ declare module '@stoprocent/bleno' {
 
         toString(): string;
 
+        getMaxValueSize(handle: ConnectionHandle): number | undefined;
+        getUpdateValueCallback(handle: ConnectionHandle): UpdateValueCallback | undefined;
+        notify(data: Buffer, handle?: ConnectionHandle | null): void;
+
         readonly RESULT_ATTR_NOT_LONG: number;
         readonly RESULT_INVALID_ATTRIBUTE_LENGTH: number;
         readonly RESULT_INVALID_OFFSET: number;
@@ -203,4 +207,4 @@ declare module '@stoprocent/bleno' {
     // Define a default export
     const BlenoDefault: Bleno;
     export default BlenoDefault;
-}
\ No newline at end of file
+}
diff --git a/lib/characteristic.js b/lib/characteristic.js
index 83bfd8d..fc17bfc 100644
--- a/lib/characteristic.js
+++ b/lib/characteristic.js
@@ -64,6 +64,10 @@ class Characteristic extends EventEmitter {
     return this._maxValueSizes.get(connection);
   }
 
+  getUpdateValueCallback (connection) {
+    return this._updateValueCallbacks.get(connection);
+  }
+
   onReadRequest (connection, offset, callback) {
     callback(this.RESULT_UNLIKELY_ERROR, null);
   }