diff --git a/.drone.yml b/.drone.yml
index 4f37dca..f865c7a 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -9,51 +9,43 @@ platform:
 steps:
 - name: vet
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make vet
-  environment:
-    GO111MODULE: on
   volumes:
   - name: gopath
     path: /go
 
 - name: lint
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make lint
-  environment:
-    GO111MODULE: on
   volumes:
   - name: gopath
     path: /go
 
 - name: misspell
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make misspell-check
-  environment:
-    GO111MODULE: on
   volumes:
   - name: gopath
     path: /go
 
 - name: embedmd
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make embedmd
-  environment:
-    GO111MODULE: on
   volumes:
   - name: gopath
     path: /go
 
 - name: test
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make test
   environment:
@@ -61,7 +53,6 @@ steps:
       from_secret: android_api_key
     ANDROID_TEST_TOKEN:
       from_secret: android_test_token
-    GO111MODULE: on
   volumes:
   - name: gopath
     path: /go
@@ -92,12 +83,11 @@ platform:
 steps:
 - name: build-push
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/amd64/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
       exclude:
@@ -105,19 +95,18 @@ steps:
 
 - name: build-tag
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.version=${DRONE_TAG##v} -X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/amd64/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
     - tag
 
 - name: executable
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - ./release/linux/amd64/gorush --help
 
@@ -173,12 +162,11 @@ platform:
 steps:
 - name: build-push
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/arm64/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
       exclude:
@@ -186,19 +174,18 @@ steps:
 
 - name: build-tag
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.version=${DRONE_TAG##v} -X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/arm64/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
     - tag
 
 - name: executable
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - ./release/linux/arm64/gorush --help
 
@@ -254,12 +241,11 @@ platform:
 steps:
 - name: build-push
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/arm/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
       exclude:
@@ -267,19 +253,18 @@ steps:
 
 - name: build-tag
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - "go build -v -ldflags '-X main.version=${DRONE_TAG##v} -X main.build=${DRONE_BUILD_NUMBER}' -a -o release/linux/arm/gorush"
   environment:
     CGO_ENABLED: 0
-    GO111MODULE: on
   when:
     event:
     - tag
 
 - name: executable
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - ./release/linux/arm/gorush --help
 
@@ -335,11 +320,9 @@ platform:
 steps:
 - name: build-all-binary
   pull: always
-  image: golang:1.12
+  image: golang:1.13
   commands:
   - make release
-  environment:
-    GO111MODULE: on
   when:
     event:
     - tag
diff --git a/go.mod b/go.mod
index 9aef3ab..c268178 100644
--- a/go.mod
+++ b/go.mod
@@ -32,6 +32,7 @@ require (
 	github.com/tidwall/rtree v0.0.0-20180113144539-6cd427091e0e // indirect
 	github.com/tidwall/tinyqueue v0.0.0-20180302190814-1e39f5511563 // indirect
 	github.com/tj/assert v0.0.0-20171129193455-018094318fb0 // indirect
+	github.com/ugorji/go v1.1.7 // indirect
 	github.com/vmihailenco/msgpack v4.0.4+incompatible // indirect
 	golang.org/x/crypto v0.0.0-20190617133340-57b3e21c3d56
 	golang.org/x/net v0.0.0-20190613194153-d28f0bde5980
diff --git a/go.sum b/go.sum
index a3bc820..7c55b7b 100644
--- a/go.sum
+++ b/go.sum
@@ -225,9 +225,13 @@ github.com/tidwall/tinyqueue v0.0.0-20180302190814-1e39f5511563/go.mod h1:mLqSmt
 github.com/tj/assert v0.0.0-20171129193455-018094318fb0 h1:Rw8kxzWo1mr6FSaYXjQELRe88y2KdfynXdnK72rdjtA=
 github.com/tj/assert v0.0.0-20171129193455-018094318fb0/go.mod h1:mZ9/Rh9oLWpLLDRpvE+3b7gP/C2YyLFYxNmcLnPTMe0=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
-github.com/ugorji/go v1.1.4 h1:j4s+tAvLfL3bZyefP2SEWmhBzmuIlH/eqNuPdFPgngw=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
+github.com/ugorji/go v1.1.7 h1:/68gy2h+1mWMrwZFeD1kQialdSzAb432dtpeJ42ovdo=
+github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
+github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8 h1:3SVOIvH7Ae1KRYyQWRjXWJEA9sS/c/pjvH++55Gr648=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
+github.com/ugorji/go/codec v1.1.7 h1:2SvQaVZ1ouYrrKKwoSk2pzd4A9evlKJb9oTL+OaLUSs=
+github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasttemplate v1.0.1 h1:tY9CJiPnMXf1ERmG2EyK7gNUd+c6RKGD0IfU8WdUSz8=
diff --git a/pipeline.libsonnet b/pipeline.libsonnet
index e5ec173..ce42246 100644
--- a/pipeline.libsonnet
+++ b/pipeline.libsonnet
@@ -9,11 +9,8 @@
     steps: [
       {
         name: 'vet',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
-        environment: {
-          GO111MODULE: 'on',
-        },
         commands: [
           'make vet',
         ],
@@ -26,11 +23,8 @@
       },
       {
         name: 'lint',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
-        environment: {
-          GO111MODULE: 'on',
-        },
         commands: [
           'make lint',
         ],
@@ -43,11 +37,8 @@
       },
       {
         name: 'misspell',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
-        environment: {
-          GO111MODULE: 'on',
-        },
         commands: [
           'make misspell-check',
         ],
@@ -60,11 +51,8 @@
       },
       {
         name: 'embedmd',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
-        environment: {
-          GO111MODULE: 'on',
-        },
         commands: [
           'make embedmd',
         ],
@@ -77,10 +65,9 @@
       },
       {
         name: 'test',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
         environment: {
-          GO111MODULE: 'on',
           ANDROID_API_KEY: { 'from_secret': 'android_api_key' },
           ANDROID_TEST_TOKEN: { 'from_secret': 'android_test_token' },
         },
@@ -127,11 +114,10 @@
     steps: [
       {
         name: 'build-push',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
         environment: {
           CGO_ENABLED: '0',
-          GO111MODULE: 'on',
         },
         commands: [
           'go build -v -ldflags \'-X main.build=${DRONE_BUILD_NUMBER}\' -a -o release/' + os + '/' + arch + '/' + name,
@@ -144,11 +130,10 @@
       },
       {
         name: 'build-tag',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
         environment: {
           CGO_ENABLED: '0',
-          GO111MODULE: 'on',
         },
         commands: [
           'go build -v -ldflags \'-X main.version=${DRONE_TAG##v} -X main.build=${DRONE_BUILD_NUMBER}\' -a -o release/' + os + '/' + arch + '/' + name,
@@ -159,7 +144,7 @@
       },
       {
         name: 'executable',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
         commands: [
           './release/' + os + '/' + arch + '/' + name + ' --help',
@@ -224,11 +209,8 @@
     steps: [
       {
         name: 'build-all-binary',
-        image: 'golang:1.12',
+        image: 'golang:1.13',
         pull: 'always',
-        environment: {
-          GO111MODULE: 'on',
-        },
         commands: [
           'make release'
         ],