diff --git a/countries.go b/countries.go
index c2c9347..3c42943 100644
--- a/countries.go
+++ b/countries.go
@@ -3,12 +3,15 @@ package sanja
 import (
 	_ "embed"
 	"encoding/json"
+	"sync"
 )
 
 //go:embed countries.json
 var countriesData []byte
 
-func getCountries() []Country {
+var getCountries = sync.OnceValue(parseCountries)
+
+func parseCountries() []Country {
 	var result []Country
 	if err := json.Unmarshal(countriesData, &result); err != nil {
 		panic("sanja: failed to parse countries data: " + err.Error())
diff --git a/country.go b/country.go
index 6f953a1..d188fbb 100644
--- a/country.go
+++ b/country.go
@@ -46,7 +46,6 @@ func (n *Normalizer) ValidatePhoneNumber(phone, countryA2 string) error {
 		return ErrInvalidPhoneNumber
 	}
 
-	
 	var matchedCode string
 	for _, code := range splitDialingCodes(country.DialingCode) {
 		if strings.HasPrefix(cleaned, "+"+code) || strings.HasPrefix(cleaned, code) {
@@ -59,7 +58,6 @@ func (n *Normalizer) ValidatePhoneNumber(phone, countryA2 string) error {
 		return fmt.Errorf("%w: expected code for %s", ErrPhoneNumberAndCountryCodeMismatch, country.Name)
 	}
 
-
 	withoutPlus := strings.TrimPrefix(cleaned, "+")
 	subscriber := withoutPlus[len(matchedCode):]