diff --git a/shell/platform/darwin/macos/framework/Source/FlutterViewController.mm b/shell/platform/darwin/macos/framework/Source/FlutterViewController.mm
index e9c26be8e0b32..4813ab8fe2279 100644
--- a/shell/platform/darwin/macos/framework/Source/FlutterViewController.mm
+++ b/shell/platform/darwin/macos/framework/Source/FlutterViewController.mm
@@ -405,7 +405,7 @@ - (void)dispatchMouseEvent:(NSEvent*)event phase:(FlutterPointerPhase)phase {
   FlutterPointerEvent flutterEvent = {
       .struct_size = sizeof(flutterEvent),
       .phase = phase,
-      .timestamp = static_cast<size_t>(event.timestamp * NSEC_PER_MSEC),
+      .timestamp = static_cast<size_t>(event.timestamp * USEC_PER_SEC),
       .x = locationInBackingCoordinates.x,
       .y = -locationInBackingCoordinates.y,  // convertPointToBacking makes this negative.
       .device_kind = kFlutterPointerDeviceKindMouse,