diff --git a/freelist.go b/freelist.go
index df544cea..88df45ca 100644
--- a/freelist.go
+++ b/freelist.go
@@ -174,7 +174,14 @@ func (f *freelist) read(p *page) {
 	copy(f.ids, ids)
 
 	// Make sure they're sorted.
-	sort.Sort(pgids(f.ids))
+	if len(f.ids) > 0 {
+		for i, v := range f.ids[:len(f.ids)-1] {
+			if f.ids[i+1] < v {
+				sort.Sort(pgids(f.ids))
+				break
+			}
+		}
+	}
 
 	// Rebuild the page cache.
 	f.reindex()