diff --git a/Dockerfile b/Dockerfile
index f708535..feed0db 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM rust:1.64-bullseye as builder
+FROM rust:1-bullseye as builder
 WORKDIR /usr/src/
 RUN cargo new myapp --vcs none
 WORKDIR /usr/src/myapp
diff --git a/src/api/systemlog.rs b/src/api/systemlog.rs
index cce18c7..b6dee4c 100644
--- a/src/api/systemlog.rs
+++ b/src/api/systemlog.rs
@@ -1,4 +1,6 @@
 use crate::api::{CurrentUser, JsonApi};
+use crate::cache::cached_user_count;
+use crate::db_conn::Db;
 use crate::random_hasher::RandomHasher;
 use crate::rds_conn::RdsConn;
 use crate::rds_models::{get_admin_list, get_candidate_list, Systemlog};
@@ -6,13 +8,19 @@ use rocket::serde::json::{json, Value};
 use rocket::State;
 
 #[get("/systemlog")]
-pub async fn get_systemlog(user: CurrentUser, rh: &State<RandomHasher>, rconn: RdsConn) -> JsonApi {
+pub async fn get_systemlog(
+    user: CurrentUser,
+    rh: &State<RandomHasher>,
+    db: Db,
+    mut rconn: RdsConn,
+) -> JsonApi {
     let logs = Systemlog::get_list(&rconn, 50).await?;
 
     Ok(json!({
         "tmp_token": rh.get_tmp_token(),
         "salt": look!(rh.salt),
         "start_time": rh.start_time.timestamp(),
+        "user_count": cached_user_count(&db, &mut rconn).await?,
         "custom_title": user.custom_title,
         "admin_list": get_admin_list(&rconn).await?,
         "candidate_list": get_candidate_list(&rconn).await?,
diff --git a/src/cache.rs b/src/cache.rs
index 501e4ee..6d771d2 100644
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -1,4 +1,5 @@
-use crate::api::CurrentUser;
+use crate::api::{Api, CurrentUser};
+use crate::db_conn::Db;
 use crate::models::{Comment, Post, User};
 use crate::rds_conn::RdsConn;
 use crate::rds_models::{clear_all, init, BlockedUsers};
@@ -10,6 +11,9 @@ use futures_util::stream::StreamExt;
 use rocket::futures::future;
 use std::collections::HashMap;
 
+const KEY_USER_COUNT: &str = "hole_v2:cache:user_count";
+const USER_COUNT_EXPIRE_TIME: usize = 5 * 60;
+
 const INSTANCE_EXPIRE_TIME: usize = 60 * 60;
 
 const MIN_LENGTH: isize = 200;
@@ -363,3 +367,16 @@ impl BlockDictCache {
         self.rconn.del(&self.key).await
     }
 }
+
+pub async fn cached_user_count(db: &Db, rconn: &mut RdsConn) -> Api<i64> {
+    let cnt: Option<i64> = rconn.get(KEY_USER_COUNT).await?;
+    if let Some(x) = cnt {
+        Ok(x)
+    } else {
+        let x = User::get_count(db).await?;
+        rconn
+            .set_ex(KEY_USER_COUNT, x, USER_COUNT_EXPIRE_TIME)
+            .await?;
+        Ok(x)
+    }
+}
diff --git a/src/models.rs b/src/models.rs
index 5562362..b9c948a 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -450,6 +450,11 @@ impl User {
             .unwrap();
         UserCache::clear_all(rconn).await;
     }
+
+    pub async fn get_count(db: &Db) -> QueryResult<i64> {
+        db.run(move |c| users::table.count().get_result(with_log!(c)))
+            .await
+    }
 }
 
 #[derive(Insertable)]