diff --git a/src/arena.c b/src/arena.c
index bc8fd28f..fcbd57e1 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -968,7 +968,7 @@ arena_decay_stashed(tsdn_t *tsdn, arena_t *arena,
 		arena_stats_add_u64(tsdn, &arena->stats, &decay->stats->purged,
 		    npurged);
 		arena_stats_sub_zu(tsdn, &arena->stats, &arena->stats.mapped,
-		    nunmapped);
+		    nunmapped << LG_PAGE);
 		arena_stats_unlock(tsdn, &arena->stats);
 	}