diff --git a/Makefile b/Makefile
index a766b17..f86983f 100644
--- a/Makefile
+++ b/Makefile
@@ -5,3 +5,12 @@ build:
 
 run:
 	sudo go run ./cmd/mullvadclosest/*.go
+
+test:
+	go test -v ./...
+
+fmt:
+	go fmt ./...
+
+lint:
+	golangci-lint run
diff --git a/cmd/mullvadclosest/main.go b/cmd/mullvadclosest/main.go
index 9ac2941..7d1eee8 100644
--- a/cmd/mullvadclosest/main.go
+++ b/cmd/mullvadclosest/main.go
@@ -2,8 +2,9 @@ package main
 
 import (
 	"encoding/json"
+	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math"
 	"math/rand"
 	"net/http"
@@ -23,15 +24,15 @@ type RelayLatency struct {
 
 // MullvadIPResponse represents the response from the Mullvad IP check API
 type MullvadIPResponse struct {
-	IP                   string `json:"ip"`
-	Country              string `json:"country"`
-	City                 string `json:"city"`
-	Longitude            float64 `json:"longitude"`
-	Latitude             float64 `json:"latitude"`
-	MullvadExitIP        bool   `json:"mullvad_exit_ip"`
-	MullvadExitIPHostname string `json:"mullvad_exit_ip_hostname,omitempty"`
-	MullvadServerType    string `json:"mullvad_server_type,omitempty"`
-	Blacklisted          struct {
+	IP                    string  `json:"ip"`
+	Country               string  `json:"country"`
+	City                  string  `json:"city"`
+	Longitude             float64 `json:"longitude"`
+	Latitude              float64 `json:"latitude"`
+	MullvadExitIP         bool    `json:"mullvad_exit_ip"`
+	MullvadExitIPHostname string  `json:"mullvad_exit_ip_hostname,omitempty"`
+	MullvadServerType     string  `json:"mullvad_server_type,omitempty"`
+	Blacklisted           struct {
 		Blacklisted bool     `json:"blacklisted"`
 		Results     []string `json:"results"`
 	} `json:"blacklisted"`
@@ -46,7 +47,7 @@ func livenessWorker(id int, jobs <-chan Relay, results chan<- RelayLatency, wg *
 		if err == nil && isLive {
 			results <- RelayLatency{Relay: relay, Latency: latency}
 		}
-		bar.Add(1)
+		_ = bar.Add(1)
 	}
 }
 
@@ -61,7 +62,7 @@ func latencyWorker(id int, jobs <-chan RelayLatency, results chan<- RelayLatency
 				Latency: latency,
 			}
 		}
-		bar.Add(1)
+		_ = bar.Add(1)
 	}
 }
 
@@ -203,7 +204,7 @@ func CheckMullvadExitIP() (bool, error) {
 	}
 	defer resp.Body.Close()
 
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return false, fmt.Errorf("failed to read response body: %v", err)
 	}
@@ -217,6 +218,10 @@ func CheckMullvadExitIP() (bool, error) {
 }
 
 func main() {
+	// Define force flag
+	force := flag.Bool("force", false, "Force execution even when connected to VPN")
+	flag.Parse()
+
 	currentUser, err := user.Current()
 	if err != nil {
 		panic("Failed to get current user")
@@ -231,8 +236,9 @@ func main() {
 		panic(fmt.Sprintf("Error checking Mullvad exit IP: %v", err))
 	}
 
-	if isMullvadExitIP {
+	if isMullvadExitIP && !*force {
 		fmt.Println("This program is designed to test latency between your actual IP and the Mullvad VPN servers. Please disconnect from the VPN and run the program again.")
+		fmt.Println("Use -force flag to bypass this check.")
 		return
 	}
 
diff --git a/cmd/mullvadclosest/relays.go b/cmd/mullvadclosest/relays.go
index ed12728..a3d02cd 100644
--- a/cmd/mullvadclosest/relays.go
+++ b/cmd/mullvadclosest/relays.go
@@ -3,7 +3,6 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"time"
 
@@ -46,7 +45,9 @@ func (r Relay) CheckLiveness() (bool, time.Duration, error) {
 	pinger.Count = 1
 	pinger.Timeout = 3 * time.Second // Increased timeout for the single ping
 	pinger.SetPrivileged(true)
-	pinger.Run()
+	if err := pinger.Run(); err != nil {
+		return false, 0, err
+	}
 	stats := pinger.Statistics()
 	if stats.PacketsRecv == 0 {
 		return false, 0, nil
@@ -64,7 +65,9 @@ func (r Relay) MeasureLatency() (time.Duration, error) {
 	pinger.Interval = 1 * time.Second // Adding interval between pings
 	pinger.Timeout = 10 * time.Second // Increased overall timeout
 	pinger.SetPrivileged(true)
-	pinger.Run()
+	if err := pinger.Run(); err != nil {
+		return 0, err
+	}
 	stats := pinger.Statistics()
 	return stats.MinRtt, nil
 }
@@ -110,7 +113,7 @@ func ParseRelayData() ([]Relay, error) {
 			return nil, fmt.Errorf("failed to read embedded file: %v", err)
 		}
 	} else {
-		fileData, err = ioutil.ReadFile(filePath)
+		fileData, err = os.ReadFile(filePath)
 		if err != nil {
 			return nil, fmt.Errorf("failed to read file: %v", err)
 		}
diff --git a/go.mod b/go.mod
index 4328d19..de016cf 100644
--- a/go.mod
+++ b/go.mod
@@ -1,15 +1,20 @@
 module sneak.berlin/go/mullvadclosest
 
-go 1.22.3
+go 1.23.0
+
+toolchain go1.24.4
+
+require (
+	github.com/go-ping/ping v1.1.0
+	github.com/schollz/progressbar/v3 v3.14.3
+)
 
 require (
-	github.com/go-ping/ping v1.1.0 // indirect
 	github.com/google/uuid v1.2.0 // indirect
 	github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
-	github.com/schollz/progressbar/v3 v3.14.3 // indirect
-	golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4 // indirect
+	golang.org/x/net v0.42.0 // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
-	golang.org/x/sys v0.20.0 // indirect
-	golang.org/x/term v0.20.0 // indirect
+	golang.org/x/sys v0.34.0 // indirect
+	golang.org/x/term v0.33.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 3f74013..6179f41 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,5 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-ping/ping v1.1.0 h1:3MCGhVX4fyEUuhsfwPrsEdQw6xspHkv5zHsiSoDFZYw=
 github.com/go-ping/ping v1.1.0/go.mod h1:xIFjORFzTxqIV/tDVGO4eDy/bLuSyawEeojSm3GfRGk=
@@ -8,25 +9,32 @@ github.com/k0kubun/go-ansi v0.0.0-20180517002512-3bf9e2903213/go.mod h1:vNUNkEQ1
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db h1:62I3jR2EmQ4l5rM/4FEfDWcRD+abF5XlKShorW5LRoQ=
 github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db/go.mod h1:l0dey0ia/Uv7NcFFVbCLtqEBQbrT4OCwCSKTEv6enCw=
+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/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/schollz/progressbar/v3 v3.14.3 h1:oOuWW19ka12wxYU1XblR4n16wF/2Y1dBLMarMo6p4xU=
 github.com/schollz/progressbar/v3 v3.14.3/go.mod h1:aT3UQ7yGm+2ZjeXPqsjTenwL3ddUiuZ0kfQ/2tHlyNI=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4 h1:b0LrWgu8+q7z4J+0Y3Umo5q1dL7NXBkKBWkaVkAq17E=
 golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
+golang.org/x/net v0.42.0 h1:jzkYrhi3YQWD6MLBJcsklgQsoAcw89EcZbJw8Z614hs=
+golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005 h1:pDMpM2zh2MT0kHy037cKlSby2nEhD50SYqwQk76Nm40=
 golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
+golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
+golang.org/x/term v0.33.0 h1:NuFncQrRcaRvVmgRkvM3j/F00gWIAlcmlB8ACEKmGIg=
+golang.org/x/term v0.33.0/go.mod h1:s18+ql9tYWp1IfpV9DmCtQDDSRBUjKaw9M1eAv5UeF0=
 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=