diff --git a/lib/libmemstat/memstat_uma.c b/lib/libmemstat/memstat_uma.c
index 8e89585300b..20cd5208fdd 100644
--- a/lib/libmemstat/memstat_uma.c
+++ b/lib/libmemstat/memstat_uma.c
@@ -29,6 +29,7 @@
 #include <sys/param.h>
 #include <sys/cpuset.h>
 #include <sys/sysctl.h>
+#include <sys/_task.h>
 
 #include <vm/vm.h>
 #include <vm/vm_page.h>