diff --git a/src/emucore/Cart3E.cxx b/src/emucore/Cart3E.cxx
index 0947d783e..963fd14de 100644
--- a/src/emucore/Cart3E.cxx
+++ b/src/emucore/Cart3E.cxx
@@ -220,6 +220,12 @@ uInt16 Cartridge3E::bankCount() const
   return 256 + 32;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt16 Cartridge3E::bankSize(uInt16 bank) const
+{
+  return 2_KB; // we cannot use bankCount() here, because it delivers wrong numbers
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool Cartridge3E::patch(uInt16 address, uInt8 value)
 {
diff --git a/src/emucore/Cart3E.hxx b/src/emucore/Cart3E.hxx
index 554560fd5..021497c82 100644
--- a/src/emucore/Cart3E.hxx
+++ b/src/emucore/Cart3E.hxx
@@ -111,6 +111,14 @@ class Cartridge3E : public Cartridge
     */
     uInt16 bankCount() const override;
 
+    /**
+      Get the size of a bank.
+
+      @param bank  The bank to get the size for
+      @return  The bank's size
+    */
+    virtual uInt16 bankSize(uInt16 bank = 0) const;
+
     /**
       Patch the cartridge ROM.