diff --git a/sys/geom/nop/g_nop.c b/sys/geom/nop/g_nop.c
index 67161cc5cfe1..98469427501a 100644
--- a/sys/geom/nop/g_nop.c
+++ b/sys/geom/nop/g_nop.c
@@ -176,6 +176,10 @@ g_nop_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
 		gctl_error(req, "Invalid secsize for provider %s.", pp->name);
 		return (EINVAL);
 	}
+	if (secsize > MAXPHYS) {
+		gctl_error(req, "secsize is too big.");
+		return (EINVAL);
+	}
 	size -= size % secsize;
 	snprintf(name, sizeof(name), "%s%s", pp->name, G_NOP_SUFFIX);
 	LIST_FOREACH(gp, &mp->geom, geom) {