diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 991c948..8c4cf7c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -18,17 +18,7 @@ jobs:
       with:
         go-version: ^1.18
       id: go
-
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
-
-    - name: Get dependencies
-      run: |
-        go get -v -t -d ./...
-        if [ -f Gopkg.toml ]; then
-            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
-            dep ensure
-        fi
-
-    - name: Build
-      run: go build -v cmd/dyndns-netcup-go/main.go
+    - name: CI Tasks
+      run: make ci
diff --git a/.gitignore b/.gitignore
index aad5f3c..a325194 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
 config.yml
-go.sum
 dyndns-netcup-go
 dist/
diff --git a/Makefile b/Makefile
index 328cc14..59b827f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,8 @@
 DIST_DIR ?= $(shell pwd)/dist
 
+ci: clean lint
+.PHONY: ci
+
 build:
 	@echo "Building release artifacts"
 	./scripts/make-releases.sh $(DIST_DIR)
@@ -9,3 +12,9 @@ clean:
 	@echo "Cleaning artifacts"
 	@rm -rf $(DIST_DIR)
 .PHONY: clean
+
+lint:
+	@echo "Linting sources"
+	@docker run --rm -v $(shell pwd):/app -w /app golangci/golangci-lint:v1.43.0 golangci-lint run -v
+.PHONY: lint
+
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..c2e4c43
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,29 @@
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5 h1:2M3HP5CCK1Si9FQhwnzYhXdG6DXeebvUHFpre8QvbyI=
+golang.org/x/lint v0.0.0-20201208152925-83fdc39ff7b5/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
+golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/internal/cache.go b/internal/cache.go
index 7cc311d..92bdb3e 100644
--- a/internal/cache.go
+++ b/internal/cache.go
@@ -41,7 +41,10 @@ func NewCache(location string, timeout time.Duration) (*Cache, error) {
 		location += defaultDir
 
 		if _, err := os.Stat(location); os.IsNotExist(err) {
-			os.MkdirAll(location, 0700)
+			err = os.MkdirAll(location, 0700)
+			if err != nil {
+				return nil, err
+			}
 		}
 
 		location += "/" + defaultIPCache
@@ -55,7 +58,6 @@ func NewCache(location string, timeout time.Duration) (*Cache, error) {
 // was made before the cache timeout it will ignore the file content.
 func (c *Cache) Load() error {
 	csvfile, err := os.Open(c.location)
-	defer csvfile.Close()
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil
@@ -68,7 +70,7 @@ func (c *Cache) Load() error {
 		return err
 	}
 
-	if time.Now().Sub(fileinfo.ModTime()) > c.timeout {
+	if time.Since(fileinfo.ModTime()) > c.timeout {
 		return nil
 	}
 
@@ -92,7 +94,7 @@ func (c *Cache) Load() error {
 		c.entries = append(c.entries, entry)
 	}
 
-	return nil
+	return csvfile.Close()
 }
 
 // SetIPv4 sets the ipv4 address for a specified domain and host to
diff --git a/pkg/netcup/response.go b/pkg/netcup/response.go
index 20cb381..33cedd4 100644
--- a/pkg/netcup/response.go
+++ b/pkg/netcup/response.go
@@ -88,10 +88,6 @@ func NewDNSRecord(hostname, dnstype, destination string) *DNSRecord {
 	}
 }
 
-func (r *Response) isError() bool {
-	return r.Status == "error"
-}
-
 func (r *Response) isSuccess() bool {
 	return r.Status == "success"
 }