diff --git a/src/renderer/diagram/controller.ts b/src/renderer/diagram/controller.ts
index 9ae3df0..33e0857 100644
--- a/src/renderer/diagram/controller.ts
+++ b/src/renderer/diagram/controller.ts
@@ -345,15 +345,11 @@ export class DiagramController {
     this.settings = { ...this.settings, ...patch }
     const s = this.settings
     if (this.paper) {
-      // Some grid runtime methods are undeclared in the shipped d.ts.
-      const paper = this.paper as unknown as {
-        drawGrid: (opt: unknown) => void
-        clearGrid: () => void
-      }
-      this.paper.options.gridSize = s.gridSize
+      // setGrid (not drawGrid) is the runtime API in JointJS 4; it is missing
+      // from the shipped d.ts so we reach it through a narrow cast.
+      const paper = this.paper as unknown as { setGrid: (opt: unknown) => void }
       this.paper.setGridSize(s.gridSize)
-      if (s.showGrid) paper.drawGrid({ name: 'mesh', args: { color: '#2a2c36' } })
-      else paper.clearGrid()
+      paper.setGrid(s.showGrid ? { name: 'mesh', args: { color: '#2a2c36' } } : false)
       this.paper.drawBackground({ color: s.theme === 'dark' ? '#181920' : '#f4f5f7' })
       this.paper.options.defaultRouter = routerConfig(s)
       this.paper.options.defaultConnector = connectorConfig(s)