diff --git a/src/math/all_test.go b/src/math/all_test.go
index 4838ffc5e1..968a7b1837 100644
--- a/src/math/all_test.go
+++ b/src/math/all_test.go
@@ -234,6 +234,18 @@ var expm1 = []float64{
 	1.842068661871398836913874273e-02,
 	-8.3193870863553801814961137573e-02,
 }
+var expm1Large = []float64{
+	4.2031418113550844e+21,
+	4.0690789717473863e+33,
+	-0.9372627915981363e+00,
+	-1.0,
+	7.077694784145933e+41,
+	5.117936223839153e+12,
+	5.124137759001189e+22,
+	7.03546003972584e+11,
+	8.456921800389698e+07,
+	-1.0,
+}
 var exp2 = []float64{
 	3.1537839463286288034313104e+01,
 	2.1361549283756232296144849e+02,
@@ -1987,6 +1999,12 @@ func TestExpm1(t *testing.T) {
 			t.Errorf("Expm1(%g) = %g, want %g", a, f, expm1[i])
 		}
 	}
+	for i := 0; i < len(vf); i++ {
+		a := vf[i] * 10
+		if f := Expm1(a); !close(expm1Large[i], f) {
+			t.Errorf("Expm1(%g) = %g, want %g", a, f, expm1Large[i])
+		}
+	}
 	for i := 0; i < len(vfexpm1SC); i++ {
 		if f := Expm1(vfexpm1SC[i]); !alike(expm1SC[i], f) {
 			t.Errorf("Expm1(%g) = %g, want %g", vfexpm1SC[i], f, expm1SC[i])
diff --git a/src/math/expm1.go b/src/math/expm1.go
index 064e131161..670b96de5e 100644
--- a/src/math/expm1.go
+++ b/src/math/expm1.go
@@ -227,7 +227,7 @@ func expm1(x float64) float64 {
 			y = Float64frombits(Float64bits(y) + uint64(k)<<52) // add k to y's exponent
 			return y
 		}
-		t := Float64frombits(uint64((0x3ff - k) << 52)) // 2**-k
+		t := Float64frombits(uint64(0x3ff-k) << 52) // 2**-k
 		y := x - (e + t)
 		y += 1
 		y = Float64frombits(Float64bits(y) + uint64(k)<<52) // add k to y's exponent