diff --git a/commands.go b/commands.go
index 2bc10d6..7f10a2f 100644
--- a/commands.go
+++ b/commands.go
@@ -978,13 +978,16 @@ func (c *commandable) SUnionStore(destination string, keys ...string) *IntCmd {
 
 //------------------------------------------------------------------------------
 
+// Sorted set member.
 type Z struct {
 	Score  float64
-	Member string
+	Member interface{}
 }
 
+// Sorted set store operation.
 type ZStore struct {
-	Weights   []int64
+	Weights []int64
+	// Can be SUM, MIN or MAX.
 	Aggregate string
 }
 
diff --git a/commands_test.go b/commands_test.go
index ae0535e..6cd9fc0 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -1822,21 +1822,43 @@ var _ = Describe("Commands", func() {
 	Describe("sorted sets", func() {
 
 		It("should ZAdd", func() {
-			zAdd := client.ZAdd("zset", redis.Z{1, "one"})
-			Expect(zAdd.Err()).NotTo(HaveOccurred())
-			Expect(zAdd.Val()).To(Equal(int64(1)))
+			added, err := client.ZAdd("zset", redis.Z{1, "one"}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
 
-			zAdd = client.ZAdd("zset", redis.Z{1, "uno"})
-			Expect(zAdd.Err()).NotTo(HaveOccurred())
-			Expect(zAdd.Val()).To(Equal(int64(1)))
+			added, err = client.ZAdd("zset", redis.Z{1, "uno"}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
 
-			zAdd = client.ZAdd("zset", redis.Z{2, "two"})
-			Expect(zAdd.Err()).NotTo(HaveOccurred())
-			Expect(zAdd.Val()).To(Equal(int64(1)))
+			added, err = client.ZAdd("zset", redis.Z{2, "two"}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
 
-			zAdd = client.ZAdd("zset", redis.Z{3, "two"})
-			Expect(zAdd.Err()).NotTo(HaveOccurred())
-			Expect(zAdd.Val()).To(Equal(int64(0)))
+			added, err = client.ZAdd("zset", redis.Z{3, "two"}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(0)))
+
+			val, err := client.ZRangeWithScores("zset", 0, -1).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(val).To(Equal([]redis.Z{{1, "one"}, {1, "uno"}, {3, "two"}}))
+		})
+
+		It("should ZAdd bytes", func() {
+			added, err := client.ZAdd("zset", redis.Z{1, []byte("one")}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
+
+			added, err = client.ZAdd("zset", redis.Z{1, []byte("uno")}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
+
+			added, err = client.ZAdd("zset", redis.Z{2, []byte("two")}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(1)))
+
+			added, err = client.ZAdd("zset", redis.Z{3, []byte("two")}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(added).To(Equal(int64(0)))
 
 			val, err := client.ZRangeWithScores("zset", 0, -1).Result()
 			Expect(err).NotTo(HaveOccurred())