diff --git a/testdata/script/gomod.txtar b/testdata/script/gomod.txtar
index 90f13a8..faf86da 100644
--- a/testdata/script/gomod.txtar
+++ b/testdata/script/gomod.txtar
@@ -1,5 +1,7 @@
 # Test various edge cases with go.mod files.
 
+[!go1.21] skip 'Go 1.20 or older cannot parse these go.mod files'
+
 exec gofumpt toolchain-stable/a.go
 stdout '//gofumpt:diagnose.* -lang=v1.21'