diff --git a/config.yaml.example b/config.yaml.example
index 81b1bc7..36ab435 100644
--- a/config.yaml.example
+++ b/config.yaml.example
@@ -4,6 +4,7 @@ redis_url: redis://redis:6379
 relay_bind: 0.0.0.0:8080
 relay_domain: relay.toot.yukimochi.jp
 relay_servicename: YUKIMOCHI Toot Relay Service
+job_concurrency: 50
 # relay_summary: |
 
 # relay_icon: https://
diff --git a/readme.md b/readme.md
index e31275e..598f452 100644
--- a/readme.md
+++ b/readme.md
@@ -33,6 +33,7 @@ redis_url: redis://redis:6379
 relay_bind: 0.0.0.0:8080
 relay_domain: relay.toot.yukimochi.jp
 relay_servicename: YUKIMOCHI Toot Relay Service
+job_concurrency: 50
 # relay_summary: |
 
 # relay_icon: https://
@@ -48,6 +49,7 @@ relay_servicename: YUKIMOCHI Toot Relay Service
  - `RELAY_BIND` (ex. `0.0.0.0:8080`)
  - `RELAY_DOMAIN` (ex. `relay.toot.yukimochi.jp`)
  - `RELAY_SERVICENAME` (ex. `YUKIMOCHI Toot Relay Service`)
+ - `JOB_CONCURRENCY` (ex. `50`)
 
 ## License
 [![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fyukimochi%2FActivity-Relay.svg?type=large)](https://app.fossa.io/projects/git%2Bgithub.com%2Fyukimochi%2FActivity-Relay?ref=badge_large)
\ No newline at end of file
diff --git a/worker/worker.go b/worker/worker.go
index 7bc8282..95c1f6e 100644
--- a/worker/worker.go
+++ b/worker/worker.go
@@ -63,6 +63,7 @@ func initConfig() {
 		viper.BindEnv("relay_bind")
 		viper.BindEnv("relay_domain")
 		viper.BindEnv("relay_servicename")
+		viper.BindEnv("job_concurrency")
 	} else {
 		Actor.Summary = viper.GetString("relay_summary")
 		Actor.Icon = activitypub.Image{URL: viper.GetString("relay_icon")}
@@ -112,7 +113,7 @@ func main() {
 	}
 
 	workerID := uuid.NewV4()
-	worker := machineryServer.NewWorker(workerID.String(), 20)
+	worker := machineryServer.NewWorker(workerID.String(), viper.GetInt("job_concurrency"))
 	err = worker.Launch()
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)