diff --git a/types/d3-graphviz/index.d.ts b/types/d3-graphviz/index.d.ts
index 52547bb101..aab3955658 100644
--- a/types/d3-graphviz/index.d.ts
+++ b/types/d3-graphviz/index.d.ts
@@ -7,6 +7,13 @@
 import { ZoomBehavior } from 'd3-zoom'
 import { Selection } from 'd3-selection'
 
+//This should be extending d3-selection, need to check it is correct
+export interface ISelection extends Selection<any, any, HTMLElement, any> {
+    graphviz(options?: IGraphvizOptions | boolean): IGraphviz;
+    selectWithoutDataPropagation(): ISelection;
+}
+
+
 /**
  * 
  * @param selector 
@@ -34,7 +41,7 @@ export interface IGraphvizOptions {
     fit?: boolean,
 }
 
-export interface IEdgeAttributes {
+export interface IDotAttributes {
     style: any;
     URL: any;
     tooltip: any;
@@ -44,55 +51,51 @@ export interface IEdgeOptions {
     shortening: number;
 }
 
-export interface INodeAttributes {
-    URL: any;
-    tooltip: any;
-}
-
 export interface INodeOptions {
 
 }
 
 export interface IGraphviz {
-    engine(engine: string): IGraphviz;
-    addImage(path: string, width: number, height: number): IGraphviz;
+    engine(engine: string): IGraphviz; //engine should be an enum
+    addImage(path: string, width: number, height: number): IGraphviz; //Width & height can be strings, i.e. '100px'
     totalMemory(size: number): IGraphviz;
-    keyMode(keyMode: string): IGraphviz;
+    keyMode(keyMode: string): IGraphviz; //keyMode should be an enum
     fade(enable: boolean): IGraphviz;
     tweenPaths(enable: boolean): IGraphviz;
     tweenShapes(enable: boolean): IGraphviz;
     convertEqualSidedPolygons(enable: boolean): IGraphviz;
-    tweenPrecision(precision: number): IGraphviz;
+    tweenPrecision(precision: number): IGraphviz; //precision can be a string, i.e. '50%'
     growEnteringEdges(enable: boolean): IGraphviz;
     zoom(enable: boolean): IGraphviz;
-    resetZoom(transition: any): any;
+    resetZoom(transition?: any): any;
     zoomBehavior(): ZoomBehavior<any, any> | null;
     zoomSelection(): any | null;
-    zoomScaleExtent(extent: number[]): IGraphviz;
-    zoomTranslateExtent(extent: number[][]): IGraphviz;
-    render(callback: Function): IGraphviz;
-    dot(src: any, callback: () => void): any;
+    zoomScaleExtent(extent?: number[]): IGraphviz;
+    zoomTranslateExtent(extent?: number[][]): IGraphviz;
+    render(callback?: Function): IGraphviz;
+    dot(src: any, callback?: () => void): IGraphviz;
     data(): any;
     renderDot(src: string, callback?: any): IGraphviz;
-    transition: any;
-    active(name: any): any;
-    options(options: IGraphvizOptions | undefined): IGraphviz;
+    transition(name: any): IGraphviz;
+    active(name?: any): any; //Returns a transition, what type?
+    options(): IGraphvizOptions;
+    options(options: IGraphvizOptions): IGraphviz;
     width(width: number): IGraphviz;
     height(height: number): IGraphviz;
     scale(scale: number): IGraphviz;
     fit(fit: boolean): IGraphviz;
-    attributer(callback: any): any;
-    on(typenames: string, callback: () => void): any;
+    attributer(callback: Function | null): IGraphviz;
+    on(typenames: string, callback?: () => void): any;
     onerror(callback: any): any;
     logEvents(enable: boolean): IGraphviz;
-    drawEdge(x1: number, x2: number, y1: number, y2: number, attributes?: IEdgeAttributes, options?: IEdgeOptions): IGraphviz;
-    updateDrawnEdge(x1: number, x2: number, y1: number, y2: number, attributes?: IEdgeAttributes, options?: IEdgeOptions): IGraphviz;
+    drawEdge(x1: number, x2: number, y1: number, y2: number, attributes?: IDotAttributes, options?: IEdgeOptions): IGraphviz;
+    updateDrawnEdge(x1: number, x2: number, y1: number, y2: number, attributes?: IDotAttributes, options?: IEdgeOptions): IGraphviz;
     moveDrawnEdgeEndPoint(x2: number, y2: number, options?: IEdgeOptions): IGraphviz;
     insertDrawnEdge(name: string): IGraphviz;
     removeDrawnEdge(): IGraphviz;
     drawnEdgeSelection(): any;
-    drawNode(x: number, y: number, nodeId: string, attributes?: INodeAttributes, options?: INodeOptions): IGraphviz;
-    updateDrawnNode(x: number, y: number, nodeId: string, attributes?: INodeAttributes, options?: INodeOptions): IGraphviz;
+    drawNode(x: number, y: number, nodeId: string, attributes?: IDotAttributes, options?: INodeOptions): IGraphviz;
+    updateDrawnNode(x: number, y: number, nodeId: string, attributes?: IDotAttributes, options?: INodeOptions): IGraphviz;
     moveDrawnNode(x: number, y: number, options?: INodeOptions): IGraphviz;
     inserDrawnNode(nodeId: string): IGraphviz;
     removeDrawnNode(): IGraphviz;