diff --git a/src/emucore/CartBUS.hxx b/src/emucore/CartBUS.hxx
index 582a78ece..27b8494e8 100644
--- a/src/emucore/CartBUS.hxx
+++ b/src/emucore/CartBUS.hxx
@@ -223,7 +223,6 @@ class CartridgeBUS : public Cartridge
     void setDatastreamPointer(uInt8 index, uInt32 value);
 
     uInt32 getDatastreamIncrement(uInt8 index) const;
-    void setDatastreamIncrement(uInt8 index, uInt32 value);
 
     uInt32 getAddressMap(uInt8 index) const;
     void setAddressMap(uInt8 index, uInt32 value);
diff --git a/src/emucore/CartCDF.hxx b/src/emucore/CartCDF.hxx
index 307ff8f0b..9dc7aa782 100644
--- a/src/emucore/CartCDF.hxx
+++ b/src/emucore/CartCDF.hxx
@@ -255,7 +255,6 @@ class CartridgeCDF : public Cartridge
     void setDatastreamPointer(uInt8 index, uInt32 value);
 
     uInt32 getDatastreamIncrement(uInt8 index) const;
-    void setDatastreamIncrement(uInt8 index, uInt32 value);
 
     uInt8 readFromDatastream(uInt8 index);