diff --git a/libpolyml/bytecode.h b/libpolyml/bytecode.h
index 0493f535..4e2df06e 100644
--- a/libpolyml/bytecode.h
+++ b/libpolyml/bytecode.h
@@ -1,84 +1,84 @@
 #pragma once
 /*
     Title: bytecode.h - Header for common code for the byte-code interpreter
 
     Copyright (c) 2006, 2015-17, 2020 David C.J. Matthews
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License version 2.1 as published by the Free Software Foundation.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
 
     You should have received a copy of the GNU Lesser General Public
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 */
 #ifndef BYTECODE_H_INCLUDED
 #define BYTECODE_H_INCLUDED
 
 #include "globals.h"
 
 class TaskData;
 
 class ByteCodeInterpreter
 {
 protected:
     ByteCodeInterpreter(stackItem **spAddr, stackItem **slAddr);
     ~ByteCodeInterpreter();
 
     enum _returnValue {
         ReturnTailCall,
         ReturnCall,
         ReturnReturn
     };
     enum _returnValue RunInterpreter(TaskData* taskData);
 
     virtual void ClearExceptionPacket() = 0;
     virtual PolyWord GetExceptionPacket() = 0; // Exception packet is set via TaskData::SetException
     virtual stackItem* GetHandlerRegister() = 0;
     virtual void SetHandlerRegister(stackItem* hr) = 0;
     virtual void HandleStackOverflow(uintptr_t space) = 0;
 
     void GarbageCollect(ScanAddress* process);
     bool mixedCode;
     int numTailArguments;
     POLYCODEPTR     interpreterPc;
     stackItem       **stackPointerAddress, **stackLimitAddress;
 
 private:
     PolyObject *overflowPacket, *dividePacket;
 
     // Update the copies in the task object
-    virtual void SaveInterpreterState(POLYCODEPTR pc, stackItem* sp)
+    void SaveInterpreterState(POLYCODEPTR pc, stackItem* sp)
     {
         interpreterPc = pc;
         *stackPointerAddress = sp;
     }
 
     // Update the local state
-    virtual void LoadInterpreterState(POLYCODEPTR& pc, stackItem*& sp)
+    void LoadInterpreterState(POLYCODEPTR& pc, stackItem*& sp)
     {
         pc = interpreterPc;
         sp = *stackPointerAddress;
     }
-private:
+
     inline PolyObject* allocateMemory(TaskData* taskData, POLYUNSIGNED words, POLYCODEPTR& pc, stackItem*& sp);
     inline PolyObject* boxDouble(TaskData* taskData, double d, POLYCODEPTR& pc, stackItem*& sp);
     inline double unboxDouble(PolyWord p);
     inline float unboxFloat(PolyWord p);
     inline PolyObject* boxFloat(TaskData* taskData, float f, POLYCODEPTR& pc, stackItem*& sp);
 
 #ifdef PROFILEOPCODES
     unsigned frequency[256], arg1Value[256], arg2Value[256];
 #endif
 };
 
 extern struct _entrypts byteCodeEPT[];
 
 #endif