Index: pmap.c
===================================================================
--- pmap.c	(revision 253553)
+++ pmap.c	(working copy)
@@ -4431,7 +4431,7 @@
 					pte = (pt_entry_t *)PHYS_TO_DMAP(tpte &
 					    PG_FRAME);
 					pte = &pte[pmap_pte_index(pv->pv_va)];
-					tpte = *pte;
+					tpte = *pte & ~PG_PTE_PAT;
 				}
 				if ((tpte & PG_V) == 0) {
 					panic("bad pte va %lx pte %lx",