diff --git a/cros/hardware_chromeos.cc b/cros/hardware_chromeos.cc
index a57cd78..ad0a64d 100644
--- a/cros/hardware_chromeos.cc
+++ b/cros/hardware_chromeos.cc
@@ -363,4 +363,9 @@
   return ErrorCode::kSuccess;
 }
 
+const char* HardwareChromeOS::GetPartitionMountOptions(
+    const std::string& partition_name) const {
+  return "";
+}
+
 }  // namespace chromeos_update_engine
diff --git a/cros/hardware_chromeos.h b/cros/hardware_chromeos.h
index 8a920ef..a64f804 100644
--- a/cros/hardware_chromeos.h
+++ b/cros/hardware_chromeos.h
@@ -68,6 +68,8 @@
   ErrorCode IsPartitionUpdateValid(
       const std::string& partition_name,
       const std::string& new_version) const override;
+  const char* GetPartitionMountOptions(
+      const std::string& partition_name) const override;
 
  private:
   friend class HardwareChromeOSTest;
diff --git a/cros/platform_constants_chromeos.cc b/cros/platform_constants_chromeos.cc
index fe94a45..5a5a521 100644
--- a/cros/platform_constants_chromeos.cc
+++ b/cros/platform_constants_chromeos.cc
@@ -32,7 +32,6 @@
 const char kOmahaResponseDeadlineFile[] = "/tmp/update-check-response-deadline";
 // This directory is wiped during powerwash.
 const char kNonVolatileDirectory[] = "/var/lib/update_engine";
-const char kPostinstallMountOptions[] = "";
 
 }  // namespace constants
 }  // namespace chromeos_update_engine