diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 1d60654b553b282348f7ea70a87ea2e8153d3447..ae6c5a3d356c7a74e88884c2e813df1d08e1e315 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -31,7 +31,7 @@ struct vkms_writeback_job {
 struct vkms_composer {
 	struct drm_framebuffer fb;
 	struct drm_rect src, dst;
-	struct iosys_map map[4];
+	struct iosys_map map[DRM_FORMAT_MAX_PLANES];
 	unsigned int offset;
 	unsigned int pitch;
 	unsigned int cpp;