diff --git a/sys/conf/NOTES b/sys/conf/NOTES
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -2057,7 +2057,8 @@
 # mismatch between the mbuf size assumed by the kernel and the mbuf size
 # assumed by a module.  The only driver that currently has the ability to
 # detect a mismatch is ti(4).
-options 	MCLSHIFT=11	# mbuf cluster shift in bits, 11 == 2KB
+options 	MCLSHIFT=12	# mbuf cluster shift in bits, 12 == 4 kB
+				#   default is 11 == 2 kB
 options 	MSIZE=256	# mbuf size in bytes
 
 #
diff --git a/sys/dev/cxgbe/adapter.h b/sys/dev/cxgbe/adapter.h
--- a/sys/dev/cxgbe/adapter.h
+++ b/sys/dev/cxgbe/adapter.h
@@ -107,7 +107,11 @@
 	CTRL_EQ_QSIZE = 1024,
 	TX_EQ_QSIZE = 1024,
 
+#if MJUMPAGESIZE != MCLBYTES
 	SW_ZONE_SIZES = 4,	/* cluster, jumbop, jumbo9k, jumbo16k */
+#else
+	SW_ZONE_SIZES = 3,	/* cluster, jumbo9k, jumbo16k */
+#endif
 	CL_METADATA_SIZE = CACHE_LINE_SIZE,
 
 	SGE_MAX_WR_NDESC = SGE_MAX_WR_LEN / EQ_ESIZE, /* max WR size in desc */
diff --git a/sys/dev/cxgbe/t4_sge.c b/sys/dev/cxgbe/t4_sge.c
--- a/sys/dev/cxgbe/t4_sge.c
+++ b/sys/dev/cxgbe/t4_sge.c
@@ -570,7 +570,9 @@
 	}
 
 	if (largest_rx_cluster != MCLBYTES &&
+#if MJUMPAGESIZE != MCLBYTES
 	    largest_rx_cluster != MJUMPAGESIZE &&
+#endif
 	    largest_rx_cluster != MJUM9BYTES &&
 	    largest_rx_cluster != MJUM16BYTES) {
 		printf("Invalid hw.cxgbe.largest_rx_cluster value (%d),"
@@ -579,7 +581,9 @@
 	}
 
 	if (safest_rx_cluster != MCLBYTES &&
+#if MJUMPAGESIZE != MCLBYTES
 	    safest_rx_cluster != MJUMPAGESIZE &&
+#endif
 	    safest_rx_cluster != MJUM9BYTES &&
 	    safest_rx_cluster != MJUM16BYTES) {
 		printf("Invalid hw.cxgbe.safest_rx_cluster value (%d),"
@@ -718,7 +722,9 @@
 	uint16_t indsz = min(RX_COPY_THRESHOLD - 1, M_INDICATESIZE);
 	static int sw_buf_sizes[] = {
 		MCLBYTES,
+#if MJUMPAGESIZE != MCLBYTES
 		MJUMPAGESIZE,
+#endif
 		MJUM9BYTES,
 		MJUM16BYTES
 	};
@@ -855,7 +861,9 @@
 	int i, j, n;
 	static int sw_buf_sizes[] = {	/* Sorted by size */
 		MCLBYTES,
+#if MJUMPAGESIZE != MCLBYTES
 		MJUMPAGESIZE,
+#endif
 		MJUM9BYTES,
 		MJUM16BYTES
 	};
diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -61,8 +61,8 @@
 #include <vm/uma.h>
 #include <vm/uma_dbg.h>
 
-_Static_assert(MJUMPAGESIZE > MCLBYTES,
-    "Cluster must be smaller than a jumbo page");
+_Static_assert(MCLBYTES <= MJUMPAGESIZE,
+    "Cluster must not be larger than a jumbo page");
 
 /*
  * In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -885,9 +885,11 @@
 	case MCLBYTES:
 		type = EXT_CLUSTER;
 		break;
+#if MJUMPAGESIZE != MCLBYTES
 	case MJUMPAGESIZE:
 		type = EXT_JUMBOP;
 		break;
+#endif
 	case MJUM9BYTES:
 		type = EXT_JUMBO9;
 		break;
@@ -933,9 +935,11 @@
 	case MCLBYTES:
 		zone = zone_clust;
 		break;
+#if MJUMPAGESIZE != MCLBYTES
 	case MJUMPAGESIZE:
 		zone = zone_jumbop;
 		break;
+#endif
 	case MJUM9BYTES:
 		zone = zone_jumbo9;
 		break;
@@ -1055,9 +1059,11 @@
 	case EXT_CLUSTER:
 		size = MCLBYTES;
 		break;
+#if MJUMPAGESIZE != MCLBYTES
 	case EXT_JUMBOP:
 		size = MJUMPAGESIZE;
 		break;
+#endif
 	case EXT_JUMBO9:
 		size = MJUM9BYTES;
 		break;