diff --git a/common/dynamic_partition_control_interface.h b/common/dynamic_partition_control_interface.h
index a878f2e..d5db9bc 100644
--- a/common/dynamic_partition_control_interface.h
+++ b/common/dynamic_partition_control_interface.h
@@ -98,10 +98,26 @@
   // - If any error, but caller should retry after reboot, action completes with
   //   kError.
   // - If any irrecoverable failures, action completes with kDeviceCorrupted.
+  //
+  // See ResetUpdate for differences between CleanuPreviousUpdateAction and
+  // ResetUpdate.
   virtual std::unique_ptr<AbstractAction> GetCleanupPreviousUpdateAction(
       BootControlInterface* boot_control,
       PrefsInterface* prefs,
       CleanupPreviousUpdateActionDelegateInterface* delegate) = 0;
+
+  // Called after an unwanted payload has been successfully applied and the
+  // device has not yet been rebooted.
+  //
+  // For snapshot updates (Virtual A/B), it calls
+  // DeltaPerformer::ResetUpdateProgress(false /* quick */) and
+  // frees previously allocated space; the next update will need to be
+  // started over.
+  //
+  // Note: CleanupPreviousUpdateAction does not do anything if an update is in
+  // progress, while ResetUpdate() forcefully free previously
+  // allocated space for snapshot updates.
+  virtual bool ResetUpdate(PrefsInterface* prefs) = 0;
 };
 
 }  // namespace chromeos_update_engine
diff --git a/common/dynamic_partition_control_stub.cc b/common/dynamic_partition_control_stub.cc
index dee4555..1239eab 100644
--- a/common/dynamic_partition_control_stub.cc
+++ b/common/dynamic_partition_control_stub.cc
@@ -63,4 +63,8 @@
   return std::make_unique<NoOpAction>();
 }
 
+bool DynamicPartitionControlStub::ResetUpdate(PrefsInterface* prefs) {
+  return false;
+}
+
 }  // namespace chromeos_update_engine
diff --git a/common/dynamic_partition_control_stub.h b/common/dynamic_partition_control_stub.h
index ddef36d..679d028 100644
--- a/common/dynamic_partition_control_stub.h
+++ b/common/dynamic_partition_control_stub.h
@@ -45,6 +45,7 @@
       BootControlInterface* boot_control,
       PrefsInterface* prefs,
       CleanupPreviousUpdateActionDelegateInterface* delegate) override;
+  bool ResetUpdate(PrefsInterface* prefs) override;
 };
 
 }  // namespace chromeos_update_engine