diff --git a/packages/common/src/interfaces/gridOption.interface.ts b/packages/common/src/interfaces/gridOption.interface.ts
index 7d134c9e8..cff713631 100644
--- a/packages/common/src/interfaces/gridOption.interface.ts
+++ b/packages/common/src/interfaces/gridOption.interface.ts
@@ -233,8 +233,8 @@ export interface GridOption {
   /** Default prefix for SlickGrid Event names (events created in the SlickGrid and/or DataView objects) */
   defaultSlickgridEventPrefix?: string;
 
-  /** Escape hatch geared towards testing Slickgrid in jsdom based environments to circumvent the lack of stylesheet.ownerNode and clientWidth calculations */
-  devMode?: false & { ownerNodeIndex?: number; containerClientWidth?: number; };
+  /** Escape hatch geared towards testing Slickgrid in JSDOM based environments to circumvent the lack of stylesheet.ownerNode and clientWidth calculations */
+  devMode?: false | { ownerNodeIndex?: number; containerClientWidth?: number; };
 
   /** Draggable Grouping Plugin options & events */
   draggableGrouping?: DraggableGrouping;