diff --git a/bitcask.go b/bitcask.go
index b0faed5..ef21fef 100644
--- a/bitcask.go
+++ b/bitcask.go
@@ -9,8 +9,8 @@ import (
 	"strings"
 	"time"
 
-	"github.com/derekparker/trie"
 	"github.com/gofrs/flock"
+	"github.com/prologic/trie"
 )
 
 var (
diff --git a/datafile.go b/datafile.go
index 5d3440d..8139708 100644
--- a/datafile.go
+++ b/datafile.go
@@ -96,6 +96,8 @@ func (df *Datafile) Sync() error {
 }
 
 func (df *Datafile) Size() (int64, error) {
+	df.RLock()
+	defer df.RUnlock()
 	return df.offset, nil
 }
 
@@ -123,13 +125,13 @@ func (df *Datafile) Write(e pb.Entry) (int64, error) {
 		return -1, ErrReadonly
 	}
 
+	df.Lock()
+	defer df.Unlock()
+
 	e.Index = df.offset
 	e.Timestamp = time.Now().Unix()
 
-	df.Lock()
 	n, err := df.enc.Encode(&e)
-	df.Unlock()
-
 	if err != nil {
 		return -1, err
 	}
diff --git a/go.mod b/go.mod
index cb65039..9dad8bf 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,7 @@ require (
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/pkg/errors v0.8.1
 	github.com/prologic/msgbus v0.1.1
+	github.com/prologic/trie v0.0.0-20190316011403-395e39dac705
 	github.com/prometheus/client_golang v0.9.2 // indirect
 	github.com/sirupsen/logrus v1.3.0
 	github.com/spf13/cobra v0.0.3
diff --git a/go.sum b/go.sum
index 3248a97..87a050f 100644
--- a/go.sum
+++ b/go.sum
@@ -42,6 +42,8 @@ github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prologic/msgbus v0.1.1/go.mod h1:B3Qu4/U2FP08x93jUzp9E8bl155+cIgDH2DUGRK6OZk=
+github.com/prologic/trie v0.0.0-20190316011403-395e39dac705 h1:2J+cSlAeECj0lfMKSmM7n5OlIio+yLovaKLZJzwLc6U=
+github.com/prologic/trie v0.0.0-20190316011403-395e39dac705/go.mod h1:LFuDmpHJGmciXd8Rl5YMhVlLMps9gz2GtYLzwxrFhzs=
 github.com/prometheus/client_golang v0.9.2 h1:awm861/B8OKDd2I/6o1dy3ra4BamzKhYOiGItCeZ740=
 github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=