diff --git a/cmd/buildmetadata/main.go b/cmd/buildmetadata/main.go
index 4a6a6d1..d00196e 100644
--- a/cmd/buildmetadata/main.go
+++ b/cmd/buildmetadata/main.go
@@ -15,6 +15,7 @@ import (
 	"strings"
 
 	"github.com/nyaruka/phonenumbers"
+	"golang.org/x/exp/maps"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -200,7 +201,12 @@ func buildPrefixMetadata(srcDir, varName, dstFile string) error {
 	output.WriteString("package phonenumbers\n\n")
 	output.WriteString(fmt.Sprintf("var %s = map[string]string {\n", varName))
 
-	for lang, mappings := range languageMappings {
+	langs := maps.Keys(languageMappings)
+	sort.Strings(langs)
+
+	for _, lang := range langs {
+		mappings := languageMappings[lang]
+
 		// iterate through our map, creating our full set of values and prefixes
 		prefixes := make([]int, 0, len(mappings))
 		seenValues := make(map[string]bool)
diff --git a/go.mod b/go.mod
index 9963055..f3bacaf 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.19
 
 require (
 	github.com/stretchr/testify v1.8.4
+	golang.org/x/exp v0.0.0-20231214170342-aacd6d4b4611
 	golang.org/x/text v0.14.0
 	google.golang.org/protobuf v1.31.0
 )
diff --git a/go.sum b/go.sum
index 31b2458..59b0bda 100644
--- a/go.sum
+++ b/go.sum
@@ -1,15 +1,16 @@
 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/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 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/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/exp v0.0.0-20231214170342-aacd6d4b4611 h1:qCEDpW1G+vcj3Y7Fy52pEM1AWm3abj8WimGYejI3SC4=
+golang.org/x/exp v0.0.0-20231214170342-aacd6d4b4611/go.mod h1:iRJReGqOEeBhDZGkGbynYwcHlctCvnjTYIamk7uXpHI=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=