diff --git a/lib/libprocstat/zfs.c b/lib/libprocstat/zfs.c
index aa6d78e..5383e65 100644
--- a/lib/libprocstat/zfs.c
+++ b/lib/libprocstat/zfs.c
@@ -35,6 +35,7 @@
 
 #undef lbolt
 #undef lbolt64
+#undef gethrestime
 #undef gethrestime_sec
 #include <sys/zfs_context.h>
 #include <sys/spa.h>