diff --git a/common/fake_hardware.h b/common/fake_hardware.h
index 29ba607..6c25183 100644
--- a/common/fake_hardware.h
+++ b/common/fake_hardware.h
@@ -216,6 +216,17 @@
     return utils::IsTimestampNewer(old_version, new_version);
   }
 
+  const char* GetPartitionMountOptions(
+      const std::string& partition_name) const override {
+#ifdef __ANDROID__
+    // TODO(allight): This matches the declaration in hardware_android.cc but
+    // ideally shouldn't be duplicated.
+    return "defcontext=u:object_r:postinstall_file:s0";
+#else
+    return "";
+#endif
+  }
+
  private:
   bool is_official_build_{true};
   bool is_normal_boot_mode_{true};
diff --git a/common/hardware_interface.h b/common/hardware_interface.h
index 7460097..4e820f1 100644
--- a/common/hardware_interface.h
+++ b/common/hardware_interface.h
@@ -160,6 +160,9 @@
   virtual ErrorCode IsPartitionUpdateValid(
       const std::string& partition_name,
       const std::string& new_version) const = 0;
+
+  virtual const char* GetPartitionMountOptions(
+      const std::string& partition_name) const = 0;
 };
 
 }  // namespace chromeos_update_engine
diff --git a/common/platform_constants.h b/common/platform_constants.h
index c060133..06399e5 100644
--- a/common/platform_constants.h
+++ b/common/platform_constants.h
@@ -54,10 +54,6 @@
 // The stateful directory used by update_engine.
 extern const char kNonVolatileDirectory[];
 
-// Options passed to the filesystem when mounting the new partition during
-// postinstall.
-extern const char kPostinstallMountOptions[];
-
 #ifdef __ANDROID_RECOVERY__
 constexpr bool kIsRecovery = true;
 #else