diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
index 2ac069b16ff..e9e43b86692 100644
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -378,9 +378,11 @@ mb_ctor_clust(void *mem, int size, void *arg, int how)
 		case MCLBYTES:
 			type = EXT_CLUSTER;
 			break;
+#if MJUM4BYTES != MCLBYTES
 		case MJUM4BYTES:
 			type = EXT_JUMBO4;
 			break;
+#endif
 		case MJUM9BYTES:
 			type = EXT_JUMBO9;
 			break;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 05a4b9ae1c0..878a6cda636 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -421,9 +421,11 @@ m_getjcl(int how, short type, int flags, int size)
 	case MCLBYTES:
 		zone = zone_clust;
 		break;
+#if MJUM4BYTES != MCLBYTES
 	case MJUM4BYTES:
 		zone = zone_jumbo4;
 		break;
+#endif
 	case MJUM9BYTES:
 		zone = zone_jumbo9;
 		break;
@@ -485,9 +487,11 @@ m_cljget(struct mbuf *m, int how, int size)
 	case MCLBYTES:
 		zone = zone_clust;
 		break;
+#if MJUM4BYTES != MCLBYTES
 	case MJUM4BYTES:
 		zone = zone_jumbo4;
 		break;
+#endif
 	case MJUM9BYTES:
 		zone = zone_jumbo9;
 		break;