diff --git a/types/graphviz/graphviz-tests.ts b/types/graphviz/graphviz-tests.ts
index 05d4c599bc0e47..d796b0bf8aa1c2 100644
--- a/types/graphviz/graphviz-tests.ts
+++ b/types/graphviz/graphviz-tests.ts
@@ -10,6 +10,9 @@ n1.set("style", "filled");
 // Add node (ID: World)
 g.addNode("World");
 
+const g_h: graphviz.Node = g.getNode("Hello");
+g_h.set("shape", "star");
+
 // Add edge between the two nodes
 const e: graphviz.Edge = g.addEdge(n1, "World");
 e.set("color", "red");
diff --git a/types/graphviz/index.d.ts b/types/graphviz/index.d.ts
index d6cc1ba5c68213..9b7c52b869b082 100644
--- a/types/graphviz/index.d.ts
+++ b/types/graphviz/index.d.ts
@@ -2,8 +2,11 @@
 // Project: https://github.com/glejeune/node-graphviz
 // Definitions by: Matt Frantz <https://github.com/mhfrantz>,
 //                 Kamontat Chantrachirathumrong <https://github.com/kamontat>
+//                 Kirill Ivanov <https://github.com/koorya>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
+/// <reference types="node" />
+
 export type PossibleValue = string | number | boolean;
 
 export type RenderType = string;
@@ -27,7 +30,7 @@ export interface Node extends HasAttributes {
 export interface Edge extends HasAttributes {}
 
 export interface OutputCallback {
-    (data: string): void;
+    (data: Buffer): void;
 }
 
 export interface ErrorCallback {
@@ -72,6 +75,7 @@ export interface Graph extends HasAttributes {
     use: RenderEngine;
 
     addNode(id: string, attrs?: any): Node;
+    getNode(id: string): Node;
     nodeCount(): number;
 
     addEdge(nodeOne: string | Node, nodeTwo: string | Node, attrs?: Options): Edge;