diff --git a/libs/pbd/cpus.cc b/libs/pbd/cpus.cc
index 80c40162ea..77b95a455d 100644
--- a/libs/pbd/cpus.cc
+++ b/libs/pbd/cpus.cc
@@ -25,7 +25,7 @@
 #ifdef __linux__
 #include <unistd.h>
 #elif defined(__APPLE__) || defined(__FreeBSD__)
-#include <sys/stddef.h>
+#include <stddef.h>
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #endif