diff --git a/libs/ardour/vst3_module.cc b/libs/ardour/vst3_module.cc
index dc3fb0fa02..1446154e1b 100644
--- a/libs/ardour/vst3_module.cc
+++ b/libs/ardour/vst3_module.cc
@@ -16,6 +16,10 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#if (__cplusplus < 201103L)
+#  define nullptr 0
+#endif
+
 #ifdef __APPLE__
 #include <Carbon/Carbon.h>
 #elif defined PLATFORM_WINDOWS