diff --git a/libc/kernel/uapi/drm/drm.h b/libc/kernel/uapi/drm/drm.h
index d28c054..251deeb 100644
--- a/libc/kernel/uapi/drm/drm.h
+++ b/libc/kernel/uapi/drm/drm.h
@@ -360,6 +360,7 @@
 #define DRM_CAP_CURSOR_HEIGHT 0x9
 #define DRM_CAP_ADDFB2_MODIFIERS 0x10
 #define DRM_CAP_PAGE_FLIP_TARGET 0x11
+#define DRM_CAP_CRTC_IN_VBLANK_EVENT 0x12
 struct drm_get_cap {
   __u64 capability;
   __u64 value;
@@ -490,7 +491,7 @@
   __u32 tv_sec;
   __u32 tv_usec;
   __u32 sequence;
-  __u32 reserved;
+  __u32 crtc_id;
 };
 typedef struct drm_clip_rect drm_clip_rect_t;
 typedef struct drm_drawable_info drm_drawable_info_t;