diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index 8809240ebbf3..6592bd2020ae 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -213,7 +213,7 @@
 #endif
 
 #if !__has_extension(c_thread_local)
-#if (defined(__cplusplus) && __cplusplus >= 201103L) ||
+#if (defined(__cplusplus) && __cplusplus >= 201103L) || \
     __has_extension(cxx_thread_local)
 #define	_Thread_local		thread_local
 #else