diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 9dd3ed8..2d128eb 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1027,5 +1027,6 @@
 extern void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 				 int *bpp);
 extern int drm_format_num_planes(uint32_t format);
+extern int drm_format_plane_cpp(uint32_t format, int plane);
 
 #endif /* __DRM_CRTC_H__ */