diff --git a/libbsd.py b/libbsd.py
index b784cd63..e983623f 100644
--- a/libbsd.py
+++ b/libbsd.py
@@ -161,6 +161,7 @@ class rtems(builder.Module):
                 'rtems/ipsec_get_policylen.c',
                 'rtems/rtems-bsd-arp-processor.c',
                 'rtems/rtems-bsd-allocator-domain-size.c',
+                'rtems/rtems-bsd-cxx.cc',
                 'rtems/rtems-bsd-get-allocator-domain-size.c',
                 'rtems/rtems-bsd-get-ethernet-addr.c',
                 'rtems/rtems-bsd-get-mac-address.c',
diff --git a/rtemsbsd/rtems/rtems-bsd-cxx.cc b/rtemsbsd/rtems/rtems-bsd-cxx.cc
index 8ae13d47..aadb25af 100644
--- a/rtemsbsd/rtems/rtems-bsd-cxx.cc
+++ b/rtemsbsd/rtems/rtems-bsd-cxx.cc
@@ -32,6 +32,8 @@
 #define __STDC_LIMIT_MACROS
 #define __STDC_CONSTANT_MACROS
 
+#include <machine/rtems-bsd-kernel-space.h>
+
 /*
  * Include this outside the extern "C", since we may include <atomic> via
  * <rtems.h> which uses templates.
@@ -40,10 +42,9 @@
 
 extern "C" {
 
-#include <machine/rtems-bsd-kernel-space.h>
-
 #include <sys/param.h>
 #include <sys/types.h>
+#include <sys/lock.h>
 #include <sys/mbuf.h>
 #include <sys/malloc.h>
 #include <sys/kernel.h>