diff --git a/app/geodata/download_test.go b/app/geodata/download_test.go
index c7e225aa7..981ebab77 100644
--- a/app/geodata/download_test.go
+++ b/app/geodata/download_test.go
@@ -7,10 +7,13 @@ import (
 	"net/http/httptest"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	commongeodata "github.com/xtls/xray-core/common/geodata"
 	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/serial"
+	"github.com/xtls/xray-core/core"
 	"github.com/yuin/gopher-lua/parse"
 	"google.golang.org/protobuf/proto"
 )
@@ -71,3 +74,41 @@ func TestDownloadOneLuaGuard(t *testing.T) {
 		})
 	}
 }
+
+func TestProtobufConfigValidation(t *testing.T) {
+	server, err := core.New(&core.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = server.Close() })
+	for _, tc := range []struct {
+		name      string
+		config    *Config
+		wantError string
+	}{
+		{"minutely cron", &Config{Cron: "* * * * *"}, ""},
+		{"minimum interval", &Config{Cron: "@every 1m"}, ""},
+		{"short interval", &Config{Cron: "@every 59s"}, "interval must be at least 1 minute"},
+		{"fractional interval", &Config{Cron: "@every 59.999s"}, "interval must be at least 1 minute"},
+		{"invalid cron", &Config{Cron: "invalid"}, "invalid geodata cron"},
+		{"dat extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.dat"}}}, ""},
+		{"uppercase extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.DAT"}}}, ""},
+		{"invalid extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.lua"}}}, "extension must be .dat"},
+		{"missing extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset"}}}, "extension must be .dat"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			config, err := serial.ToTypedMessage(tc.config).GetInstance()
+			if err != nil {
+				t.Fatal(err)
+			}
+			_, err = core.CreateObject(server, config)
+			if tc.wantError == "" {
+				if err != nil {
+					t.Fatal(err)
+				}
+			} else if err == nil || !strings.Contains(err.Error(), tc.wantError) {
+				t.Fatalf("CreateObject() error = %v; want %q", err, tc.wantError)
+			}
+		})
+	}
+}
diff --git a/app/geodata/geodata.go b/app/geodata/geodata.go
index 5b0111a81..334020615 100644
--- a/app/geodata/geodata.go
+++ b/app/geodata/geodata.go
@@ -2,7 +2,10 @@ package geodata
 
 import (
 	"context"
+	"path/filepath"
+	"strings"
 	"sync"
+	"time"
 
 	"github.com/robfig/cron/v3"
 	"github.com/xtls/xray-core/common"
@@ -25,6 +28,18 @@ func New(ctx context.Context, config *Config) (*Instance, error) {
 	if config.Cron == "" {
 		return &Instance{}, nil
 	}
+	for _, asset := range config.Assets {
+		if !strings.EqualFold(filepath.Ext(asset.GetFile()), ".dat") {
+			return nil, errors.New("geodata asset file extension must be .dat")
+		}
+	}
+	schedule, err := cron.ParseStandard(config.Cron)
+	if err != nil {
+		return nil, errors.New("invalid geodata cron").Base(err)
+	}
+	if interval, ok := schedule.(cron.ConstantDelaySchedule); ok && interval.Delay < time.Minute {
+		return nil, errors.New("geodata cron interval must be at least 1 minute")
+	}
 
 	g := &Instance{
 		assets: config.Assets,
@@ -44,9 +59,7 @@ func New(ctx context.Context, config *Config) (*Instance, error) {
 		cron.WithChain(cron.SkipIfStillRunning(cron.DiscardLogger)),
 		cron.WithLogger(cron.DiscardLogger),
 	)
-	if _, err := g.tasker.AddFunc(config.Cron, g.execute); err != nil {
-		return nil, errors.New("invalid geodata cron").Base(err)
-	}
+	g.tasker.Schedule(schedule, cron.FuncJob(g.execute))
 	errors.LogInfo(ctx, "scheduled geodata reload with cron: ", config.Cron)
 
 	return g, nil
diff --git a/infra/conf/geodata.go b/infra/conf/geodata.go
index 42b0961bf..f79a37e23 100644
--- a/infra/conf/geodata.go
+++ b/infra/conf/geodata.go
@@ -4,7 +4,6 @@ import (
 	"net/url"
 	"path/filepath"
 	"strings"
-	"time"
 
 	"github.com/robfig/cron/v3"
 	"github.com/xtls/xray-core/app/geodata"
@@ -45,17 +44,6 @@ func validateHTTPS(s string) error {
 	return nil
 }
 
-func validateGeodataCron(spec string) error {
-	schedule, err := cron.ParseStandard(spec)
-	if err != nil {
-		return err
-	}
-	if interval, ok := schedule.(cron.ConstantDelaySchedule); ok && interval.Delay < time.Minute {
-		return errors.New("interval must be at least 1 minute")
-	}
-	return nil
-}
-
 type GeodataConfig struct {
 	Cron     *string               `json:"cron"`
 	Outbound string                `json:"outbound"`
@@ -66,7 +54,7 @@ func (c *GeodataConfig) Build() (proto.Message, error) {
 	config := &geodata.Config{}
 
 	if c.Cron != nil {
-		if err := validateGeodataCron(*c.Cron); err != nil {
+		if _, err := cron.ParseStandard(*c.Cron); err != nil {
 			return nil, errors.New("invalid geodata cron").Base(err)
 		}
 		config.Cron = *c.Cron
diff --git a/infra/conf/geodata_test.go b/infra/conf/geodata_test.go
index 97fe03087..4944d850a 100644
--- a/infra/conf/geodata_test.go
+++ b/infra/conf/geodata_test.go
@@ -106,42 +106,3 @@ func TestGeodataAssetConfigFileExtension(t *testing.T) {
 		}
 	}
 }
-
-func TestGeodataConfigCronFrequency(t *testing.T) {
-	for _, tc := range []struct {
-		cron      string
-		wantError string
-	}{
-		{"0 * * * *", ""},
-		{"15 */2 * * *", ""},
-		{"0 4 * * *", ""},
-		{"*/60 * * * *", ""},
-		{"0,0 * * * *", ""},
-		{"CRON_TZ=Asia/Singapore 30 * * * *", ""},
-		{"@hourly", ""},
-		{"@daily", ""},
-		{"@every 1m", ""},
-		{"@every 1h", ""},
-		{"@every 1h30m", ""},
-		{"* * * * *", ""},
-		{"*/30 * * * *", ""},
-		{"0,59 4 * * *", ""},
-		{"0-1 4 1 1 *", ""},
-		{"@every 59m59s", ""},
-		{"@every 1s", "interval must be at least 1 minute"},
-		{"@every 59s", "interval must be at least 1 minute"},
-		{"@every 59.999s", "interval must be at least 1 minute"},
-		{"invalid", "invalid geodata cron"},
-	} {
-		t.Run(tc.cron, func(t *testing.T) {
-			_, err := (&GeodataConfig{Cron: &tc.cron}).Build()
-			if tc.wantError == "" {
-				if err != nil {
-					t.Fatal(err)
-				}
-			} else if err == nil || !strings.Contains(err.Error(), tc.wantError) {
-				t.Fatalf("Build() error = %v; want %q", err, tc.wantError)
-			}
-		})
-	}
-}