diff --git a/.golangci.toml b/.golangci.toml
new file mode 100644
index 0000000..9776f20
--- /dev/null
+++ b/.golangci.toml
@@ -0,0 +1,39 @@
+[run]
+  deadline = "2m"
+  skip-files = []
+
+[linters-settings]
+
+  [linters-settings.govet]
+    check-shadowing = true
+
+  [linters-settings.gocyclo]
+    min-complexity = 12.0
+
+  [linters-settings.maligned]
+    suggest-new = true
+
+  [linters-settings.goconst]
+    min-len = 3.0
+    min-occurrences = 3.0
+
+  [linters-settings.misspell]
+    locale = "US"
+
+[linters]
+  enable-all = true
+  disable = [
+    "maligned",
+    "lll",
+    "gas",
+    "dupl",
+    "prealloc",
+    "gochecknoglobals",
+    "gochecknoinits",
+  ]
+
+[issues]
+  exclude-use-default = false
+  max-per-linter = 0
+  max-same-issues = 0
+  exclude = []
diff --git a/.travis.yml b/.travis.yml
index 3e0e861..a04236e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,10 @@ cache:
   directories:
     - $GOPATH/pkg/mod
 
+branches:
+  only:
+    - master
+
 notifications:
   email:
     on_success: never
@@ -15,6 +19,11 @@ notifications:
 env:
   - GO111MODULE=on
 
+before_install:
+  # Install linters and misspell
+  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $GOPATH/bin ${GOLANGCI_LINT_VERSION}
+  - golangci-lint --version
+
 install:
   - go mod tidy
   - git diff --exit-code go.mod
@@ -22,5 +31,5 @@ install:
   - go mod download
 
 script:
-  - make build
+  - make
   - make image
diff --git a/Makefile b/Makefile
index 2b93505..34b6081 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,15 @@
-.PHONY: default build image
+.PHONY: default build image check
 
-default: build
+default: check test build
+
+test:
+	go test -v -cover ./...
 
 build:
 	CGO_ENABLED=0 go build -a --installsuffix cgo --ldflags="-s" -o whoami
 
 image:
 	docker build -t containous/whoami .
+
+check:
+	golangci-lint run
diff --git a/app.go b/app.go
index f8d9511..d52124e 100644
--- a/app.go
+++ b/app.go
@@ -19,6 +19,7 @@ import (
 	"github.com/gorilla/websocket"
 )
 
+// Units
 const (
 	_        = iota
 	KB int64 = 1 << (10 * iota)
@@ -110,13 +111,13 @@ func dataHandler(w http.ResponseWriter, r *http.Request) {
 	unit := queryParams.Get("unit")
 	switch strings.ToLower(unit) {
 	case "kb":
-		size = size * KB
+		size *= KB
 	case "mb":
-		size = size * MB
+		size *= MB
 	case "gb":
-		size = size * GB
+		size *= GB
 	case "tb":
-		size = size * TB
+		size *= TB
 	}
 
 	attachment, err := strconv.ParseBool(queryParams.Get("attachment"))
@@ -248,7 +249,7 @@ func healthHandler(w http.ResponseWriter, req *http.Request) {
 
 func fillContent(length int64) io.ReadSeeker {
 	charset := "-ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-	b := make([]byte, length, length)
+	b := make([]byte, length)
 
 	for i := range b {
 		b[i] = charset[i%len(charset)]