diff --git a/morris.js/index.d.ts b/morris.js/index.d.ts
index 9193615fdf..5c5ddf811f 100644
--- a/morris.js/index.d.ts
+++ b/morris.js/index.d.ts
@@ -37,7 +37,11 @@ declare namespace morris {
         /** Set the font family of the axis labels (default: sans-serif). */
         gridTextFamily?: string;
         /** Set the font weight of the axis labels (default: normal). */
-        gridTextWeight?: string;
+        gridTextWeight?: string;      
+        /** Set the stroke of the grid. (default: 0.5)*/
+        gridStrokeWidth?: number;
+        /** Set the line color of the grid. (default: #aaa) */
+        gridLineColor?: string;
     }
 
     interface ILineOptions extends IGridChartOptions {
@@ -147,4 +151,4 @@ declare module "morris" {
     export = Morris;
 }
 
-declare var Morris: morris.MorrisStatic;
\ No newline at end of file
+declare var Morris: morris.MorrisStatic;