diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index a3a90c6dcce1..ceee8f5a14ea 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -1287,9 +1287,11 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
 		access &= ~VM_PROT_WRITE;
 
 	/*
-	 * Loop through all of the pages in the entry's range, copying each
-	 * one from the source object (it should be there) to the destination
-	 * object.
+	 * Loop through all of the pages in the entry's range, copying
+	 * each one from the source object (it should be there) to the
+	 * destination object.  Note that copied pages are not wired
+	 * and marked dirty to prevent reclamation without saving the
+	 * content into the swap file on pageout.
 	 */
 	for (vaddr = dst_entry->start, dst_pindex = 0;
 	    vaddr < dst_entry->end;
@@ -1332,6 +1334,7 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
 		pmap_copy_page(src_m, dst_m);
 		VM_OBJECT_UNLOCK(object);
 		dst_m->valid = VM_PAGE_BITS_ALL;
+		dst_m->dirty = VM_PAGE_BITS_ALL;
 		VM_OBJECT_UNLOCK(dst_object);
 
 		/*