diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index 1693ce0c43d..6f290be0d51 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -32,6 +32,7 @@ extern "C"
 #include <mach/message.h>
 #include <mach/notify.h>
 #include <mach/vm_attributes.h>
+#include <mach/vm_param.h>
 
 #include <hurd.h>
 #include <hurd/interrupt.h>