diff --git a/src/libCom/osi/os/Darwin/systemCallIntMech.cpp b/src/libCom/osi/os/Darwin/systemCallIntMech.cpp
deleted file mode 100644
index bdac4ef7c..000000000
--- a/src/libCom/osi/os/Darwin/systemCallIntMech.cpp
+++ /dev/null
@@ -1,23 +0,0 @@
-
-/*************************************************************************\
-* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
-*     National Laboratory.
-* Copyright (c) 2002 The Regents of the University of California, as
-*     Operator of Los Alamos National Laboratory.
-* EPICS BASE Versions 3.13.7
-* and higher are distributed subject to a Software License Agreement found
-* in file LICENSE that is included with this distribution. 
-\*************************************************************************/
-/* $Id$ */
-/*
- *      Author:		Jeff Hill 
- */
-
-#include "osiSock.h"
-
-enum epicsSocketSystemCallInterruptMechanismQueryInfo 
-        epicsSocketSystemCallInterruptMechanismQuery ()
-{
-    return esscimqi_socketSigAlarmRequired;
-    /*return esscimqi_socketBothShutdownRequired;*/
-}
diff --git a/src/libCom/osi/os/Linux/systemCallIntMech.cpp b/src/libCom/osi/os/Linux/systemCallIntMech.cpp
deleted file mode 100644
index 2cd37b1aa..000000000
--- a/src/libCom/osi/os/Linux/systemCallIntMech.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-
-/*************************************************************************\
-* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
-*     National Laboratory.
-* Copyright (c) 2002 The Regents of the University of California, as
-*     Operator of Los Alamos National Laboratory.
-* EPICS BASE Versions 3.13.7
-* and higher are distributed subject to a Software License Agreement found
-* in file LICENSE that is included with this distribution. 
-\*************************************************************************/
-/* $Id$ */
-/*
- *      Author:		Jeff Hill 
- */
-
-#include "osiSock.h"
-
-enum epicsSocketSystemCallInterruptMechanismQueryInfo 
-        epicsSocketSystemCallInterruptMechanismQuery ()
-{
-    return esscimqi_socketBothShutdownRequired;
-}
diff --git a/src/libCom/osi/os/RTEMS/systemCallIntMech.cpp b/src/libCom/osi/os/RTEMS/systemCallIntMech.cpp
deleted file mode 100644
index 2cd37b1aa..000000000
--- a/src/libCom/osi/os/RTEMS/systemCallIntMech.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-
-/*************************************************************************\
-* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
-*     National Laboratory.
-* Copyright (c) 2002 The Regents of the University of California, as
-*     Operator of Los Alamos National Laboratory.
-* EPICS BASE Versions 3.13.7
-* and higher are distributed subject to a Software License Agreement found
-* in file LICENSE that is included with this distribution. 
-\*************************************************************************/
-/* $Id$ */
-/*
- *      Author:		Jeff Hill 
- */
-
-#include "osiSock.h"
-
-enum epicsSocketSystemCallInterruptMechanismQueryInfo 
-        epicsSocketSystemCallInterruptMechanismQuery ()
-{
-    return esscimqi_socketBothShutdownRequired;
-}
diff --git a/src/libCom/osi/os/cygwin32/systemCallIntMech.cpp b/src/libCom/osi/os/cygwin32/systemCallIntMech.cpp
index 5b755139e..c31bcef2d 100644
--- a/src/libCom/osi/os/cygwin32/systemCallIntMech.cpp
+++ b/src/libCom/osi/os/cygwin32/systemCallIntMech.cpp
@@ -19,5 +19,5 @@
 enum epicsSocketSystemCallInterruptMechanismQueryInfo 
         epicsSocketSystemCallInterruptMechanismQuery ()
 {
-    return esscimqi_socketBothShutdownRequired;
+    return esscimqi_socketCloseRequired;
 }
diff --git a/src/libCom/osi/os/posix/systemCallIntMech.cpp b/src/libCom/osi/os/posix/systemCallIntMech.cpp
index 1fe5f6559..2cd37b1aa 100644
--- a/src/libCom/osi/os/posix/systemCallIntMech.cpp
+++ b/src/libCom/osi/os/posix/systemCallIntMech.cpp
@@ -18,5 +18,5 @@
 enum epicsSocketSystemCallInterruptMechanismQueryInfo 
         epicsSocketSystemCallInterruptMechanismQuery ()
 {
-    return esscimqi_socketSigAlarmRequired;
+    return esscimqi_socketBothShutdownRequired;
 }
diff --git a/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp b/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp
deleted file mode 100644
index 2cd37b1aa..000000000
--- a/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-
-/*************************************************************************\
-* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
-*     National Laboratory.
-* Copyright (c) 2002 The Regents of the University of California, as
-*     Operator of Los Alamos National Laboratory.
-* EPICS BASE Versions 3.13.7
-* and higher are distributed subject to a Software License Agreement found
-* in file LICENSE that is included with this distribution. 
-\*************************************************************************/
-/* $Id$ */
-/*
- *      Author:		Jeff Hill 
- */
-
-#include "osiSock.h"
-
-enum epicsSocketSystemCallInterruptMechanismQueryInfo 
-        epicsSocketSystemCallInterruptMechanismQuery ()
-{
-    return esscimqi_socketBothShutdownRequired;
-}