diff --git a/store/mdb/batch.go b/store/mdb/batch.go
index d8debf6..d68ee43 100644
--- a/store/mdb/batch.go
+++ b/store/mdb/batch.go
@@ -15,6 +15,9 @@ func (w *WriteBatch) Close() error {
 }
 
 func (w *WriteBatch) Put(key, value []byte) {
+	if value == nil {
+		value = []byte{}
+	}
 	w.wb = append(w.wb, Write{key, value})
 }
 
diff --git a/store/store_test.go b/store/store_test.go
index f37c496..c79bddd 100644
--- a/store/store_test.go
+++ b/store/store_test.go
@@ -37,6 +37,16 @@ func testSimple(db *DB, t *testing.T) {
 	} else if v != nil {
 		t.Fatal("must nil")
 	}
+
+	if err := db.Put(key, nil); err != nil {
+		t.Fatal(err)
+	}
+
+	if v, err := db.Get(key); err != nil {
+		t.Fatal(err)
+	} else if !bytes.Equal(v, []byte{}) {
+		t.Fatal("must empty")
+	}
 }
 
 func testBatch(db *DB, t *testing.T) {
@@ -80,7 +90,27 @@ func testBatch(db *DB, t *testing.T) {
 		t.Fatal(string(v))
 	}
 
+	wb.Put(key1, nil)
+	wb.Put(key2, []byte{})
+
+	if err := wb.Commit(); err != nil {
+		t.Fatal(err)
+	}
+
+	if v, err := db.Get(key1); err != nil {
+		t.Fatal(err)
+	} else if !bytes.Equal(v, []byte{}) {
+		t.Fatal("must empty")
+	}
+
+	if v, err := db.Get(key2); err != nil {
+		t.Fatal(err)
+	} else if !bytes.Equal(v, []byte{}) {
+		t.Fatal("must empty")
+	}
+
 	db.Delete(key1)
+	db.Delete(key2)
 }
 
 func checkIterator(it *RangeLimitIterator, cv ...int) error {