diff --git a/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp b/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp
index a57c3b57d..2cd37b1aa 100644
--- a/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp
+++ b/src/libCom/osi/os/vxWorks/systemCallIntMech.cpp
@@ -18,5 +18,5 @@
 enum epicsSocketSystemCallInterruptMechanismQueryInfo 
         epicsSocketSystemCallInterruptMechanismQuery ()
 {
-    return esscimqi_socketCloseRequired;
+    return esscimqi_socketBothShutdownRequired;
 }