diff --git a/platformhisi.h b/platformhisi.h
index 927da17..14a58b9 100644
--- a/platformhisi.h
+++ b/platformhisi.h
@@ -39,6 +39,10 @@
   bool CanImportBuffer(buffer_handle_t handle) override;
 
  private:
+  uint64_t ConvertGrallocFormatToDrmModifiers(uint64_t flags, bool is_rgb);
+
+  bool IsDrmFormatRgb(uint32_t drm_format);
+
   DrmDevice *drm_;
 
   const gralloc_module_t *gralloc_;