diff --git a/src/ca/oldAccess.h b/src/ca/oldAccess.h
index cf2b7945a..27b18f6a7 100644
--- a/src/ca/oldAccess.h
+++ b/src/ca/oldAccess.h
@@ -83,11 +83,11 @@ public:
 protected:
     ~oldChannelNotify (); // must allocate from pool
 private:
-    cacChannel & io;
     oldCAC & cacCtx;
     caCh * pConnCallBack;
     void * pPrivate;
     caArh * pAccessRightsFunc;
+    cacChannel & io;
     void connectNotify ();
     void disconnectNotify ();
     void accessRightsNotify ( const caAccessRights & );
@@ -198,6 +198,15 @@ private:
 	oldSubscription & operator = ( const oldSubscription & );
 };
 
+class oldCACMutex {
+public:
+    void lock ();
+    void unlock ();
+    void show ( unsigned level ) const;
+private:
+    epicsMutex mutex;
+};
+
 struct oldCAC : public cacNotify
 {
 public:
@@ -235,7 +244,7 @@ public:
                      int lineno, const char *pFormat, va_list args );
     bool preemptiveCallbakIsEnabled () const;
 private:
-    mutable epicsMutex mutex; 
+    mutable oldCACMutex mutex; 
     cac & clientCtx;
     caExceptionHandler *ca_exception_func;
     void *ca_exception_arg;
@@ -526,4 +535,19 @@ inline bool oldCAC::preemptiveCallbakIsEnabled () const
     return this->clientCtx.preemptiveCallbakIsEnabled ();
 }
 
+inline void oldCACMutex::lock ()
+{
+    this->mutex.lock ();
+}
+
+inline void oldCACMutex::unlock ()
+{
+    this->mutex.unlock ();
+}
+
+inline void oldCACMutex::show ( unsigned level ) const
+{
+    this->mutex.show ( level );
+}
+
 #endif // ifndef oldAccessh
diff --git a/src/ca/oldCAC.cpp b/src/ca/oldCAC.cpp
index 84cebec18..76c5dd224 100644
--- a/src/ca/oldCAC.cpp
+++ b/src/ca/oldCAC.cpp
@@ -14,6 +14,10 @@
  *	505 665 1831
  */
 
+#ifdef _MSC_VER
+#   pragma warning(disable:4355)
+#endif
+
 #include <stdio.h>
 
 #define epicsExportSharedSymbols
@@ -36,7 +40,7 @@ oldCAC::~oldCAC ()
 
 void oldCAC::changeExceptionEvent ( caExceptionHandler *pfunc, void *arg )
 {
-    epicsGuard < epicsMutex > autoMutex ( this->mutex );
+    epicsGuard < oldCACMutex > autoMutex ( this->mutex );
     this->ca_exception_func = pfunc;
     this->ca_exception_arg = arg;
 // should block here until releated callback in progress completes
@@ -44,7 +48,7 @@ void oldCAC::changeExceptionEvent ( caExceptionHandler *pfunc, void *arg )
 
 void oldCAC::replaceErrLogHandler ( caPrintfFunc *ca_printf_func )
 {
-    epicsGuard < epicsMutex > autoMutex ( this->mutex );
+    epicsGuard < oldCACMutex > autoMutex ( this->mutex );
     if ( ca_printf_func ) {
         this->pVPrintfFunc = ca_printf_func;
     }
@@ -56,7 +60,7 @@ void oldCAC::replaceErrLogHandler ( caPrintfFunc *ca_printf_func )
 
 void oldCAC::registerForFileDescriptorCallBack ( CAFDHANDLER *pFunc, void *pArg )
 {
-    epicsGuard < epicsMutex > autoMutex ( this->mutex );
+    epicsGuard < oldCACMutex > autoMutex ( this->mutex );
     this->fdRegFunc = pFunc;
     this->fdRegArg = pArg;
 // should block here until releated callback in progress completes
@@ -80,7 +84,7 @@ int oldCAC::vPrintf ( const char *pformat, va_list args ) const // X aCC 361
 {
     caPrintfFunc *pFunc;
     {
-        epicsGuard < epicsMutex > autoMutex ( this->mutex );
+        epicsGuard < oldCACMutex > autoMutex ( this->mutex );
         pFunc = this->pVPrintfFunc;
     }
     if ( pFunc ) {
@@ -98,7 +102,7 @@ void oldCAC::exception ( int stat, const char *pCtx,
     caExceptionHandler *pFunc;
     void *pArg;
     {
-        epicsGuard < epicsMutex > autoMutex ( this->mutex );
+        epicsGuard < oldCACMutex > autoMutex ( this->mutex );
         pFunc = this->ca_exception_func;
         pArg = this->ca_exception_arg;
     }
@@ -130,7 +134,7 @@ void oldCAC::exception ( int status, const char *pContext,
     caExceptionHandler *pFunc;
     void *pArg;
     {
-        epicsGuard < epicsMutex > autoMutex ( this->mutex );
+        epicsGuard < oldCACMutex > autoMutex ( this->mutex );
         pFunc = this->ca_exception_func;
         pArg = this->ca_exception_arg;
     }
@@ -163,7 +167,7 @@ void oldCAC::fdWasCreated ( int fd )
     CAFDHANDLER *pFunc;
     void *pArg;
     {
-        epicsGuard < epicsMutex > autoMutex ( this->mutex );
+        epicsGuard < oldCACMutex > autoMutex ( this->mutex );
         pFunc = this->fdRegFunc;
         pArg = this->fdRegArg;
     }
@@ -177,7 +181,7 @@ void oldCAC::fdWasDestroyed ( int fd )
     CAFDHANDLER *pFunc;
     void *pArg;
     {
-        epicsGuard < epicsMutex > autoMutex ( this->mutex );
+        epicsGuard < oldCACMutex > autoMutex ( this->mutex );
         pFunc = this->fdRegFunc;
         pArg = this->fdRegArg;
     }