diff --git a/.travis.yml b/.travis.yml
index 9207fc2..641f666 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: go
 go:
-  - 1.11.x
+  - 1.13.x
 sudo: false
 matrix:
   include:
@@ -9,7 +9,6 @@ matrix:
     - go get -u golang.org/x/lint/golint
     - go get -u golang.org/x/tools/cmd/...
     script:
-    - export GO111MODULE=on
     - go mod download
     - go test -v -race $(go list ./...)
     - go vet $(go list ./...)
@@ -23,7 +22,7 @@ matrix:
     - kill $pid
   # Using HEAD of dependencies
   - install:
-    - go get -t ./...
+    - go get -t -u ./...
     - go get -u golang.org/x/lint/golint
     - go get -u golang.org/x/tools/cmd/...
     script:
@@ -40,7 +39,7 @@ matrix:
   allow_failures:
   # Using HEAD of dependencies
   - install:
-    - go get -t ./...
+    - go get -t -u ./...
     - go get -u golang.org/x/lint/golint
     - go get -u golang.org/x/tools/cmd/...
     script:
diff --git a/cmd/chihaya/config.go b/cmd/chihaya/config.go
index 2f58848..453bd6b 100644
--- a/cmd/chihaya/config.go
+++ b/cmd/chihaya/config.go
@@ -10,17 +10,13 @@ import (
 	"github.com/chihaya/chihaya/frontend/http"
 	"github.com/chihaya/chihaya/frontend/udp"
 	"github.com/chihaya/chihaya/middleware"
-)
 
-import (
 	// Imports to register middleware drivers.
 	_ "github.com/chihaya/chihaya/middleware/clientapproval"
 	_ "github.com/chihaya/chihaya/middleware/jwt"
 	_ "github.com/chihaya/chihaya/middleware/torrentapproval"
 	_ "github.com/chihaya/chihaya/middleware/varinterval"
-)
 
-import (
 	// Imports to register storage drivers.
 	_ "github.com/chihaya/chihaya/storage/memory"
 	_ "github.com/chihaya/chihaya/storage/redis"
diff --git a/go.mod b/go.mod
index 7e8715a..ff7de27 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,7 @@
 module github.com/chihaya/chihaya
 
+go 1.13
+
 require (
 	github.com/SermoDigital/jose v0.0.0-20180104203859-803625baeddc
 	github.com/alicebob/gopher-json v0.0.0-20180125190556-5a6b3ba71ee6 // indirect