diff --git a/common/boot_control_interface.h b/common/boot_control_interface.h
index 321174e..2de21a1 100644
--- a/common/boot_control_interface.h
+++ b/common/boot_control_interface.h
@@ -93,6 +93,11 @@
   // bootloader will attempt to load the |slot| marked as active. Note that this
   // method doesn't change the value of GetCurrentSlot() on the current boot.
   virtual bool SetActiveBootSlot(Slot slot) = 0;
+  // Get the active slot. In other words, the slot which will be used on
+  // next system reboot. This should match the |slot| parameter of last
+  // successful call to |SetActiveBootSlot|.
+  // Return 0xFFFFFFFF if underlying HAL doesn't support this operation.
+  virtual Slot GetActiveBootSlot() = 0;
 
   // Mark the current slot as successfully booted asynchronously. No other slot
   // flags are modified. Returns false if it was not able to schedule the
diff --git a/common/boot_control_stub.h b/common/boot_control_stub.h
index dcddbae..3167115 100644
--- a/common/boot_control_stub.h
+++ b/common/boot_control_stub.h
@@ -56,6 +56,7 @@
   bool IsSlotBootable(BootControlInterface::Slot slot) const override;
   bool MarkSlotUnbootable(BootControlInterface::Slot slot) override;
   bool SetActiveBootSlot(BootControlInterface::Slot slot) override;
+  Slot GetActiveBootSlot() override { return kInvalidSlot; }
   bool MarkBootSuccessfulAsync(base::Callback<void(bool)> callback) override;
   bool IsSlotMarkedSuccessful(BootControlInterface::Slot slot) const override;
   DynamicPartitionControlInterface* GetDynamicPartitionControl() override;
diff --git a/common/fake_boot_control.h b/common/fake_boot_control.h
index 79e2139..8a68501 100644
--- a/common/fake_boot_control.h
+++ b/common/fake_boot_control.h
@@ -83,6 +83,7 @@
   }
 
   bool SetActiveBootSlot(Slot slot) override { return true; }
+  Slot GetActiveBootSlot() override { return kInvalidSlot; }
 
   bool MarkBootSuccessfulAsync(base::Callback<void(bool)> callback) override {
     // We run the callback directly from here to avoid having to setup a message