diff --git a/bloom.go b/bloom.go
index 7da9265..89dbe24 100644
--- a/bloom.go
+++ b/bloom.go
@@ -326,7 +326,7 @@ type bloomFilterJSON struct {
 }
 
 // MarshalJSON implements json.Marshaler interface.
-func (f *BloomFilter) MarshalJSON() ([]byte, error) {
+func (f BloomFilter) MarshalJSON() ([]byte, error) {
 	return json.Marshal(bloomFilterJSON{f.m, f.k, f.b})
 }
 
diff --git a/bloom_test.go b/bloom_test.go
index d66c99a..3f5ea2b 100644
--- a/bloom_test.go
+++ b/bloom_test.go
@@ -1,12 +1,15 @@
 package bloom
 
 import (
+	"fmt"
 	"bytes"
 	"encoding/binary"
 	"encoding/gob"
 	"encoding/json"
 	"math"
 	"testing"
+
+	"github.com/bits-and-blooms/bitset"
 )
 
 // This implementation of Bloom filters is _not_
@@ -291,6 +294,35 @@ func TestMarshalUnmarshalJSON(t *testing.T) {
 	if err != nil {
 		t.Fatal(err.Error())
 	}
+	fmt.Println(string(data))
+
+	var g BloomFilter
+	err = json.Unmarshal(data, &g)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	if g.m != f.m {
+		t.Error("invalid m value")
+	}
+	if g.k != f.k {
+		t.Error("invalid k value")
+	}
+	if g.b == nil {
+		t.Fatal("bitset is nil")
+	}
+	if !g.b.Equal(f.b) {
+		t.Error("bitsets are not equal")
+	}
+}
+
+
+func TestMarshalUnmarshalJSONValue(t *testing.T) {
+	f:= BloomFilter{1000, 4, bitset.New(1000)}
+	data, err := json.Marshal(f)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	fmt.Println(string(data))
 
 	var g BloomFilter
 	err = json.Unmarshal(data, &g)
diff --git a/go.mod b/go.mod
index 4e272f7..64d7e4d 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,6 @@ module github.com/bits-and-blooms/bloom/v3
 go 1.16
 
 require (
-	github.com/bits-and-blooms/bitset v1.8.0
+	github.com/bits-and-blooms/bitset v1.9.0
 	github.com/twmb/murmur3 v1.1.6
 )
diff --git a/go.sum b/go.sum
index 80abfd2..119b90f 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,6 @@
 github.com/bits-and-blooms/bitset v1.3.1 h1:y+qrlmq3XsWi+xZqSaueaE8ry8Y127iMxlMfqcK8p0g=
 github.com/bits-and-blooms/bitset v1.3.1/go.mod h1:gIdJ4wp64HaoK2YrL1Q5/N7Y16edYb8uY+O0FJTyyDA=
-github.com/bits-and-blooms/bitset v1.8.0 h1:FD+XqgOZDUxxZ8hzoBFuV9+cGWY9CslN6d5MS5JVb4c=
-github.com/bits-and-blooms/bitset v1.8.0/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
+github.com/bits-and-blooms/bitset v1.9.0 h1:g1YivPG8jOtrN013Fe8OBXubkiTwvm7/vG2vXz03ANU=
+github.com/bits-and-blooms/bitset v1.9.0/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
 github.com/twmb/murmur3 v1.1.6 h1:mqrRot1BRxm+Yct+vavLMou2/iJt0tNVTTC0QoIjaZg=
 github.com/twmb/murmur3 v1.1.6/go.mod h1:Qq/R7NUyOfr65zD+6Q5IHKsJLwP7exErjN6lyyq3OSQ=