diff --git a/src/emucore/CartBUS.hxx b/src/emucore/CartBUS.hxx
index 70cf61300..cce9d334c 100644
--- a/src/emucore/CartBUS.hxx
+++ b/src/emucore/CartBUS.hxx
@@ -155,7 +155,7 @@ class CartridgeBUS : public Cartridge
 
     @return The internal RAM size
   */
-  uInt32 internalRamSize() const override { return 8_KB; }
+  uInt32 internalRamSize() const override { return uInt32(myRAM.size()); }
 
   /**
     Read a byte from cart internal RAM.
diff --git a/src/emucore/CartCDF.hxx b/src/emucore/CartCDF.hxx
index d32127547..ae49e3ee9 100644
--- a/src/emucore/CartCDF.hxx
+++ b/src/emucore/CartCDF.hxx
@@ -159,7 +159,7 @@ class CartridgeCDF : public Cartridge
 
       @return The internal RAM size
     */
-    uInt32 internalRamSize() const override { return 8_KB; }
+    uInt32 internalRamSize() const override { return uInt32(myRAM.size()); }
 
     /**
       Read a byte from cart internal RAM.
diff --git a/src/emucore/CartDPCPlus.hxx b/src/emucore/CartDPCPlus.hxx
index 393fd35be..88de6c510 100644
--- a/src/emucore/CartDPCPlus.hxx
+++ b/src/emucore/CartDPCPlus.hxx
@@ -150,7 +150,7 @@ class CartridgeDPCPlus : public Cartridge
 
       @return The internal RAM size
     */
-    uInt32 internalRamSize() const override { return 8_KB; }
+    uInt32 internalRamSize() const override { return uInt32(myDPCRAM.size()); }
 
     /**
       Read a byte from cart internal RAM.