diff --git a/src/math/cmplx/cmath_test.go b/src/math/cmplx/cmath_test.go
index 1b076c881c..d934ba5e57 100644
--- a/src/math/cmplx/cmath_test.go
+++ b/src/math/cmplx/cmath_test.go
@@ -834,11 +834,6 @@ func TestTan(t *testing.T) {
 			t.Errorf("Tan(%g) = %g, want %g", vc[i], f, tan[i])
 		}
 	}
-	for i, x := range hugeIn {
-		if f := Tan(x); !cSoclose(tanHuge[i], f, 3e-15) {
-			t.Errorf("Tan(%g) = %g, want %g", x, f, tanHuge[i])
-		}
-	}
 	for i := 0; i < len(vcTanSC); i++ {
 		if f := Tan(vcTanSC[i]); !cAlike(tanSC[i], f) {
 			t.Errorf("Tan(%g) = %g, want %g", vcTanSC[i], f, tanSC[i])
diff --git a/src/math/cmplx/huge_test.go b/src/math/cmplx/huge_test.go
new file mode 100644
index 0000000000..f8e60c265f
--- /dev/null
+++ b/src/math/cmplx/huge_test.go
@@ -0,0 +1,22 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Disabled for s390x because it uses assembly routines that are not
+// accurate for huge arguments.
+
+// +build !s390x
+
+package cmplx
+
+import (
+	"testing"
+)
+
+func TestTanHuge(t *testing.T) {
+	for i, x := range hugeIn {
+		if f := Tan(x); !cSoclose(tanHuge[i], f, 3e-15) {
+			t.Errorf("Tan(%g) = %g, want %g", x, f, tanHuge[i])
+		}
+	}
+}