diff --git a/.github/workflows/build-pb-doc.yml b/.github/workflows/build-pb-doc.yml
index 5c8a225..e5084fb 100644
--- a/.github/workflows/build-pb-doc.yml
+++ b/.github/workflows/build-pb-doc.yml
@@ -26,7 +26,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: 1.22
+          go-version: 1.23
 
       - name: Install go pkgs
         run: |
diff --git a/.github/workflows/build-tzpb.yml b/.github/workflows/build-tzpb.yml
index d3fd8ee..1cd023c 100644
--- a/.github/workflows/build-tzpb.yml
+++ b/.github/workflows/build-tzpb.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ["1.21", "1.22"]
+        go: ["1.22", "1.23"]
 
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 18447e8..951c6a0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,48 +24,34 @@ jobs:
         run: |
           deno fmt --check ./README.md
 
-  golangci:
-    name: golangci-lint
+  build:
     strategy:
       matrix:
-        go: ["1.21", "1.22"]
-    permissions:
-      contents: read
-      pull-requests: read
+        go: ["1.23"]
     runs-on: ubuntu-latest
-    timeout-minutes: 15
     steps:
       - uses: actions/checkout@v4
 
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: ${{ matrix.go }}
+          go-version-file: go.mod
 
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v6
         with:
           version: latest
           args: --timeout=5m
-  build:
-    strategy:
-      matrix:
-        go: ["1.21", "1.22"]
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: ${{ matrix.go }}
+          skip-cache: true
+          skip-pkg-cache: true
+          skip-build-cache: true
 
       - name: Install go pkgs
         run: |
           make install
 
       - name: Run coverage
-        run: go test -race -coverprofile=coverage.txt -covermode=atomic
+        run: go test -coverprofile=coverage.txt -covermode=atomic
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v4
diff --git a/go.mod b/go.mod
index 7d4ff38..4192127 100644
--- a/go.mod
+++ b/go.mod
@@ -1,13 +1,12 @@
 module github.com/ringsaturn/tzf
 
-go 1.22
-toolchain go1.23.0
+go 1.23
 
 require (
 	github.com/loov/hrtime v1.0.3
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/paulmach/orb v0.11.1
-	github.com/ringsaturn/go-cities.json v0.6.1
+	github.com/ringsaturn/go-cities.json v0.6.2
 	github.com/ringsaturn/polyf v0.2.2
 	github.com/ringsaturn/tzf-rel-lite v0.0.2024-a
 	github.com/tidwall/geojson v1.4.5
diff --git a/go.sum b/go.sum
index 8731861..4193809 100644
--- a/go.sum
+++ b/go.sum
@@ -26,8 +26,8 @@ github.com/paulmach/protoscan v0.2.1/go.mod h1:SpcSwydNLrxUGSDvXvO0P7g7AuhJ7lcKf
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 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/ringsaturn/go-cities.json v0.6.1 h1:37P320/yLo0IL4+hAQYPXNPNn8pvm497BCtE74EdFIA=
-github.com/ringsaturn/go-cities.json v0.6.1/go.mod h1:RWApnQPG6nU558XXbY1try5mi9u9Hd667J6vr948VBo=
+github.com/ringsaturn/go-cities.json v0.6.2 h1:7vtbP4JowdESbLFZkcTnCVooKmsGpdk73BT7mvBHSrw=
+github.com/ringsaturn/go-cities.json v0.6.2/go.mod h1:RWApnQPG6nU558XXbY1try5mi9u9Hd667J6vr948VBo=
 github.com/ringsaturn/polyf v0.2.2 h1:71ua1Giawwpb+bvqFelcZygup+0HFuV5hYLA+8YO2ZM=
 github.com/ringsaturn/polyf v0.2.2/go.mod h1:0+PnAZooWRyH6ULFdxTC86pe15L4VT3e71CQVPG67CE=
 github.com/ringsaturn/tzf-rel-lite v0.0.2024-a h1:olA5Zh7jE5tXhtHby2hFlZWo4nZJxIzTL7ctGFOa+Uw=
diff --git a/tzf_default_finder_test.go b/tzf_default_finder_test.go
index 95fcdd8..d60d928 100644
--- a/tzf_default_finder_test.go
+++ b/tzf_default_finder_test.go
@@ -3,7 +3,6 @@ package tzf_test
 import (
 	"bytes"
 	"fmt"
-	"math/rand"
 	"runtime"
 	"testing"
 
@@ -55,7 +54,7 @@ func BenchmarkDefaultFinder_GetTimezoneName_Random_WorldCities(b *testing.B) {
 	bench := hrtesting.NewBenchmark(b)
 	defer bench.Report()
 	for bench.Next() {
-		p := gocitiesjson.Cities[rand.Intn(len(gocitiesjson.Cities))]
+		p := gocitiesjson.Random()
 		_ = defaultFinder.GetTimezoneName(p.Lng, p.Lat)
 	}
 }
diff --git a/tzf_fuzzy_test.go b/tzf_fuzzy_test.go
index 5c62c5a..41a5d12 100644
--- a/tzf_fuzzy_test.go
+++ b/tzf_fuzzy_test.go
@@ -2,7 +2,6 @@ package tzf_test
 
 import (
 	"fmt"
-	"math/rand"
 	"testing"
 
 	"github.com/loov/hrtime/hrtesting"
@@ -31,7 +30,7 @@ func init() {
 
 func TestFuzzySupports(t *testing.T) {
 	failCount := 0
-	for _, city := range gocitiesjson.Cities {
+	for city := range gocitiesjson.All(false) {
 		name := fuzzyFinder.GetTimezoneName(city.Lng, city.Lat)
 		if name == "" {
 			failCount += 1
@@ -76,7 +75,7 @@ func BenchmarkFuzzyFinder_GetTimezoneName_Random_WorldCities(b *testing.B) {
 	bench := hrtesting.NewBenchmark(b)
 	defer bench.Report()
 	for bench.Next() {
-		p := gocitiesjson.Cities[rand.Intn(len(gocitiesjson.Cities))]
+		p := gocitiesjson.Random()
 		_ = fuzzyFinder.GetTimezoneName(p.Lng, p.Lat)
 	}
 }
diff --git a/tzf_test.go b/tzf_test.go
index 6b63558..df43fd5 100644
--- a/tzf_test.go
+++ b/tzf_test.go
@@ -3,7 +3,6 @@ package tzf_test
 import (
 	"bytes"
 	"fmt"
-	"math/rand"
 	"runtime"
 	"testing"
 
@@ -48,7 +47,7 @@ func BenchmarkGetTimezoneName_Random_WorldCities(b *testing.B) {
 	bench := hrtesting.NewBenchmark(b)
 	defer bench.Report()
 	for bench.Next() {
-		p := gocitiesjson.Cities[rand.Intn(len(gocitiesjson.Cities))]
+		p := gocitiesjson.Random()
 		_ = finder.GetTimezoneName(p.Lng, p.Lat)
 	}
 }