diff --git a/src/libCom/osi/epicsThread.cpp b/src/libCom/osi/epicsThread.cpp
index 40b2e4798..e836d6958 100644
--- a/src/libCom/osi/epicsThread.cpp
+++ b/src/libCom/osi/epicsThread.cpp
@@ -321,4 +321,4 @@ extern "C" {
 } // extern "C"
 
 // Ensure the main thread gets a unique ID
-epicsThreadGetIdSelf();
+static epicsThreadId epicsThreadMainId = epicsThreadGetIdSelf();