diff --git a/src/Thread.c b/src/Thread.c
index f8b5279f..28b410aa 100644
--- a/src/Thread.c
+++ b/src/Thread.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2023 IBM Corp. and Ian Craggs
+ * Copyright (c) 2009, 2025 IBM Corp. and Ian Craggs
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
@@ -51,7 +51,9 @@
 
 #include "OsWrapper.h"
 
+#if !defined(NSEC_PER_SEC)
 #define NSEC_PER_SEC 1000000000L
+#endif
 
 /**
  * Start a new thread