diff --git a/gopls/internal/regtest/modfile/modfile_test.go b/gopls/internal/regtest/modfile/modfile_test.go
index 868aa70aa5..cca3b3cba6 100644
--- a/gopls/internal/regtest/modfile/modfile_test.go
+++ b/gopls/internal/regtest/modfile/modfile_test.go
@@ -859,6 +859,8 @@ func main() {}
 }
 
 func TestSumUpdateFixesDiagnostics(t *testing.T) {
+	t.Skipf("Skipping known-flaky test; see https://go.dev/issue/51352.")
+
 	testenv.NeedsGo1Point(t, 14)
 
 	const mod = `