diff --git a/xxhash.go b/xxhash.go
index e29a8c3..a72ee48 100644
--- a/xxhash.go
+++ b/xxhash.go
@@ -65,6 +65,13 @@ func (d *Digest) ResetWithSeed(seed uint64) {
 	d.n = 0
 }
 
+// Copy returns a copy of the Digest.
+func (d *Digest) Copy() *Digest {
+	digest := *d
+	copy(digest.mem[:], d.mem[:])
+	return &digest
+}
+
 // Size always returns 8 bytes.
 func (d *Digest) Size() int { return 8 }
 
diff --git a/xxhash_test.go b/xxhash_test.go
index 8e2f456..9b499bf 100644
--- a/xxhash_test.go
+++ b/xxhash_test.go
@@ -190,6 +190,23 @@ func TestAllocs(t *testing.T) {
 	})
 }
 
+func TestCopy(t *testing.T) {
+	want := Sum64String("abcdef")
+
+	d0 := New()
+	d0.WriteString("abc")
+	d1 := d0.Copy()
+	d0.WriteString("def")
+	d1.WriteString("def")
+
+	if got := d0.Sum64(); got != want {
+		t.Fatalf("hashing with original Digest, got 0x%x; want 0x%x", got, want)
+	}
+	if got := d1.Sum64(); got != want {
+		t.Fatalf("hashing with copied Digest, got 0x%x; want 0x%x", got, want)
+	}
+}
+
 func testAllocs(t *testing.T, fn func()) {
 	t.Helper()
 	if allocs := int(testing.AllocsPerRun(10, fn)); allocs > 0 {