diff --git a/cue/testdata/cycle/issue990.txtar b/cue/testdata/cycle/issue990.txtar
index 2a9d1b3f8c6..72c7d8efc0f 100644
--- a/cue/testdata/cycle/issue990.txtar
+++ b/cue/testdata/cycle/issue990.txtar
@@ -82,18 +82,6 @@ out.subs.subs.#p: invalid structural cycle
 This seems to be the result of incorrect handling of disjunctions.
 -- diff/todo/p3 --
 Reordering
--- diff/todo/p3 --
-Reordering
--- out/evalalpha/stats --
-Leaks:  2604
-Freed:  263
-Reused: 263
-Allocs: 2604
-Retain: 0
-
-Unifications: 239
-Conjuncts:    8656
-Disjuncts:    522
 -- out/evalalpha/stats --
 Leaks:  2075
 Freed:  218
diff --git a/internal/cuetxtar/txtar.go b/internal/cuetxtar/txtar.go
index 0fe64109564..8de05b6e0c7 100644
--- a/internal/cuetxtar/txtar.go
+++ b/internal/cuetxtar/txtar.go
@@ -483,6 +483,9 @@ func (x *TxTarTest) run(t *testing.T, m *cuetdtest.M, f func(tc *Test)) {
 			// Track the position of the fallback files.
 			index := make(map[string]int, len(a.Files))
 			for i, f := range a.Files {
+				if _, ok := index[f.Name]; ok {
+					t.Errorf("duplicated txtar file entry %s", f.Name)
+				}
 				index[f.Name] = i
 			}