diff --git a/Makefile b/Makefile
index 2d8d5e2c..d4441c47 100644
--- a/Makefile
+++ b/Makefile
@@ -90,5 +90,13 @@ go-test:  ; $(ENV) RACE='1' "$(SHELL)" ./scripts/make/go-test.sh
 
 go-check: go-tools go-lint go-test
 
+# A quick check to make sure that all supported operating systems can be
+# typechecked and built successfully.
+go-os-check:
+	env GOOS='darwin'  go vet ./internal/...
+	env GOOS='freebsd' go vet ./internal/...
+	env GOOS='linux'   go vet ./internal/...
+	env GOOS='windows' go vet ./internal/...
+
 openapi-lint: ; cd ./openapi/ && $(YARN) test
 openapi-show: ; cd ./openapi/ && $(YARN) start
diff --git a/internal/aghos/os.go b/internal/aghos/os.go
index 4d535100..827591fa 100644
--- a/internal/aghos/os.go
+++ b/internal/aghos/os.go
@@ -45,3 +45,8 @@ func RunCommand(command string, arguments ...string) (int, string, error) {
 
 	return cmd.ProcessState.ExitCode(), string(out), nil
 }
+
+// IsOpenWrt returns true if host OS is OpenWrt.
+func IsOpenWrt() (ok bool) {
+	return isOpenWrt()
+}
diff --git a/internal/aghos/os_unix.go b/internal/aghos/os_darwin.go
similarity index 89%
rename from internal/aghos/os_unix.go
rename to internal/aghos/os_darwin.go
index 5e0ffef6..1fd6ac56 100644
--- a/internal/aghos/os_unix.go
+++ b/internal/aghos/os_darwin.go
@@ -1,4 +1,4 @@
-// +build aix darwin dragonfly netbsd openbsd solaris
+// +build darwin
 
 package aghos
 
@@ -30,3 +30,7 @@ func haveAdminRights() (bool, error) {
 func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }
+
+func isOpenWrt() (ok bool) {
+	return false
+}
diff --git a/internal/aghos/os_freebsd.go b/internal/aghos/os_freebsd.go
index 40965e3a..e9004697 100644
--- a/internal/aghos/os_freebsd.go
+++ b/internal/aghos/os_freebsd.go
@@ -30,3 +30,7 @@ func haveAdminRights() (bool, error) {
 func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }
+
+func isOpenWrt() (ok bool) {
+	return false
+}
diff --git a/internal/aghos/os_linux.go b/internal/aghos/os_linux.go
index 7c74bbd0..c68ceb37 100644
--- a/internal/aghos/os_linux.go
+++ b/internal/aghos/os_linux.go
@@ -3,7 +3,11 @@
 package aghos
 
 import (
+	"bytes"
+	"io/ioutil"
 	"os"
+	"path/filepath"
+	"strings"
 	"syscall"
 
 	"github.com/AdguardTeam/golibs/log"
@@ -37,3 +41,41 @@ func haveAdminRights() (bool, error) {
 func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return syscall.Kill(pid, sig)
 }
+
+func isOpenWrt() (ok bool) {
+	const etcDir = "/etc"
+
+	// TODO(e.burkov): Take care of dealing with fs package after updating
+	// Go version to 1.16.
+	fileInfos, err := ioutil.ReadDir(etcDir)
+	if err != nil {
+		return false
+	}
+
+	// fNameSubstr is a part of a name of the desired file.
+	const fNameSubstr = "release"
+	osNameData := []byte("OpenWrt")
+
+	for _, fileInfo := range fileInfos {
+		if fileInfo.IsDir() {
+			continue
+		}
+
+		fn := fileInfo.Name()
+		if !strings.Contains(fn, fNameSubstr) {
+			continue
+		}
+
+		var body []byte
+		body, err = ioutil.ReadFile(filepath.Join(etcDir, fn))
+		if err != nil {
+			continue
+		}
+
+		if bytes.Contains(body, osNameData) {
+			return true
+		}
+	}
+
+	return false
+}
diff --git a/internal/aghos/os_windows.go b/internal/aghos/os_windows.go
index 738889b4..510d8535 100644
--- a/internal/aghos/os_windows.go
+++ b/internal/aghos/os_windows.go
@@ -40,3 +40,7 @@ func haveAdminRights() (bool, error) {
 func sendProcessSignal(pid int, sig syscall.Signal) error {
 	return fmt.Errorf("not supported on Windows")
 }
+
+func isOpenWrt() (ok bool) {
+	return false
+}
diff --git a/internal/home/service.go b/internal/home/service.go
index 4935212a..69375cef 100644
--- a/internal/home/service.go
+++ b/internal/home/service.go
@@ -10,7 +10,6 @@ import (
 	"syscall"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
-	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/kardianos/service"
 )
@@ -215,7 +214,7 @@ func handleServiceInstallCommand(s service.Service) {
 		log.Fatal(err)
 	}
 
-	if util.IsOpenWrt() {
+	if aghos.IsOpenWrt() {
 		// On OpenWrt it is important to run enable after the service installation
 		// Otherwise, the service won't start on the system startup
 		_, err = runInitdCommand("enable")
@@ -242,7 +241,7 @@ Click on the link below and follow the Installation Wizard steps to finish setup
 
 // handleServiceStatusCommand handles service "uninstall" command
 func handleServiceUninstallCommand(s service.Service) {
-	if util.IsOpenWrt() {
+	if aghos.IsOpenWrt() {
 		// On OpenWrt it is important to run disable command first
 		// as it will remove the symlink
 		_, err := runInitdCommand("disable")
@@ -290,7 +289,7 @@ func configureService(c *service.Config) {
 	c.Option["SysvScript"] = sysvScript
 
 	// On OpenWrt we're using a different type of sysvScript.
-	if util.IsOpenWrt() {
+	if aghos.IsOpenWrt() {
 		c.Option["SysvScript"] = openWrtScript
 	} else if runtime.GOOS == "freebsd" {
 		c.Option["SysvScript"] = freeBSDScript
diff --git a/internal/util/autohosts.go b/internal/util/autohosts.go
index 22602ac4..a9b63c77 100644
--- a/internal/util/autohosts.go
+++ b/internal/util/autohosts.go
@@ -1,3 +1,7 @@
+// Package util contains various utilities.
+//
+// TODO(a.garipov): Such packages are widely considered an antipattern.  Remove
+// this when we refactor our project structure.
 package util
 
 import (
@@ -13,6 +17,7 @@ import (
 	"sync"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
+	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/fsnotify/fsnotify"
 	"github.com/miekg/dns"
@@ -68,7 +73,7 @@ func (a *AutoHosts) Init(hostsFn string) {
 		a.hostsFn = hostsFn
 	}
 
-	if IsOpenWrt() {
+	if aghos.IsOpenWrt() {
 		// OpenWrt: "/tmp/hosts/dhcp.cfg01411c".
 		a.hostsDirs = append(a.hostsDirs, "/tmp/hosts")
 	}
diff --git a/internal/util/helpers.go b/internal/util/helpers.go
deleted file mode 100644
index f97635b7..00000000
--- a/internal/util/helpers.go
+++ /dev/null
@@ -1,55 +0,0 @@
-// Package util contains various utilities.
-//
-// TODO(a.garipov): Such packages are widely considered an antipattern.  Remove
-// this when we refactor our project structure.
-package util
-
-import (
-	"bytes"
-	"io/ioutil"
-	"path/filepath"
-	"runtime"
-	"strings"
-)
-
-// IsOpenWrt returns true if host OS is OpenWrt.
-func IsOpenWrt() bool {
-	if runtime.GOOS != "linux" {
-		return false
-	}
-
-	const etcDir = "/etc"
-
-	// TODO(e.burkov): Take care of dealing with fs package after updating
-	// Go version to 1.16.
-	fileInfos, err := ioutil.ReadDir(etcDir)
-	if err != nil {
-		return false
-	}
-
-	// fNameSubstr is a part of a name of the desired file.
-	const fNameSubstr = "release"
-	osNameData := []byte("OpenWrt")
-
-	for _, fileInfo := range fileInfos {
-		if fileInfo.IsDir() {
-			continue
-		}
-
-		if !strings.Contains(fileInfo.Name(), fNameSubstr) {
-			continue
-		}
-
-		var body []byte
-		body, err = ioutil.ReadFile(filepath.Join(etcDir, fileInfo.Name()))
-		if err != nil {
-			continue
-		}
-
-		if bytes.Contains(body, osNameData) {
-			return true
-		}
-	}
-
-	return false
-}
diff --git a/scripts/hooks/pre-commit b/scripts/hooks/pre-commit
index 859f536f..885e3c9f 100755
--- a/scripts/hooks/pre-commit
+++ b/scripts/hooks/pre-commit
@@ -14,7 +14,7 @@ fi
 
 if [ "$(git diff --cached --name-only -- '*.go' 'go.mod')" ]
 then
-	make go-lint go-test
+	make go-os-check go-lint go-test
 fi
 
 if [ "$(git diff --cached --name-only -- './openapi/openapi.yaml')" ]