diff --git a/hardware_chromeos.cc b/hardware_chromeos.cc
index 4b0b82f..f0f3ea9 100644
--- a/hardware_chromeos.cc
+++ b/hardware_chromeos.cc
@@ -230,6 +230,11 @@
   return true;
 }
 
+int64_t HardwareChromeOS::GetBuildTimestamp() const {
+  // TODO(senj): implement this in Chrome OS.
+  return 0;
+}
+
 void HardwareChromeOS::LoadConfig(const string& root_prefix, bool normal_mode) {
   brillo::KeyValueStore store;