diff --git a/platformdrmgeneric.h b/platformdrmgeneric.h
index ebe27b7..d46e8b0 100644
--- a/platformdrmgeneric.h
+++ b/platformdrmgeneric.h
@@ -35,6 +35,7 @@
   int ReleaseBuffer(hwc_drm_bo_t *bo) override;
 
   uint32_t ConvertHalFormatToDrm(uint32_t hal_format);
+  uint32_t DrmFormatToBitsPerPixel(uint32_t drm_format);
 
  private:
   DrmDevice *drm_;