diff --git a/src/emucore/CartEnhanced.hxx b/src/emucore/CartEnhanced.hxx
index d4e1f37b2..4d47411f2 100644
--- a/src/emucore/CartEnhanced.hxx
+++ b/src/emucore/CartEnhanced.hxx
@@ -304,6 +304,11 @@ class CartridgeEnhanced : public Cartridge
     */
     virtual bool checkSwitchBank(uInt16 address, uInt8 value) = 0;
 
+    /**
+      Calculate the number of segments supported by the cartridge.
+    */
+    virtual uInt16 calcNumSegments() const;
+
   private:
     /**
       Get the ROM's startup bank.