diff --git a/sys/geom/mirror/g_mirror_ctl.c b/sys/geom/mirror/g_mirror_ctl.c
index 529fff86b4d8..b9318e0faf94 100644
--- a/sys/geom/mirror/g_mirror_ctl.c
+++ b/sys/geom/mirror/g_mirror_ctl.c
@@ -413,6 +413,7 @@ again:
 		} else {
 			bzero(md.md_provider, sizeof(md.md_provider));
 		}
+		md.md_provsize = pp->mediasize;
 		sector = g_malloc(pp->sectorsize, M_WAITOK);
 		mirror_metadata_encode(&md, sector);
 		error = g_write_data(disks[i].consumer,
diff --git a/sys/geom/raid3/g_raid3_ctl.c b/sys/geom/raid3/g_raid3_ctl.c
index 5a4a07bd2e6f..b83b933460d6 100644
--- a/sys/geom/raid3/g_raid3_ctl.c
+++ b/sys/geom/raid3/g_raid3_ctl.c
@@ -449,6 +449,7 @@ g_raid3_ctl_insert(struct gctl_req *req, struct g_class *mp)
                 strlcpy(md.md_provider, pp->name, sizeof(md.md_provider));
         else
                 bzero(md.md_provider, sizeof(md.md_provider));
+	md.md_provsize = pp->mediasize;
 	sector = g_malloc(pp->sectorsize, M_WAITOK);
 	raid3_metadata_encode(&md, sector);
 	g_topology_unlock();