diff --git a/lib/ns/interfacemgr.c b/lib/ns/interfacemgr.c
index c17010c789..37e58ae25c 100644
--- a/lib/ns/interfacemgr.c
+++ b/lib/ns/interfacemgr.c
@@ -638,11 +638,13 @@ ns_interface_shutdown(ns_interface_t *ifp) {
 
 static void
 ns_interface_destroy(ns_interface_t *ifp) {
-	isc_mem_t *mctx = ifp->mgr->mctx;
+	isc_mem_t *mctx;
 	int disp;
 
 	REQUIRE(NS_INTERFACE_VALID(ifp));
 
+	mctx = ifp->mgr->mctx;
+
 	ns_interface_shutdown(ifp);
 
 	for (disp = 0; disp < ifp->nudpdispatch; disp++)