diff --git a/src/backend/hotcold.rs b/src/backend/hotcold.rs
index 16e23d8..94872ac 100644
--- a/src/backend/hotcold.rs
+++ b/src/backend/hotcold.rs
@@ -73,7 +73,9 @@ impl<BE: WriteBackend> WriteBackend for HotColdBackend<BE> {
 
     async fn write_bytes(&self, tpe: FileType, id: &Id, buf: Vec<u8>) -> Result<()> {
         if let Some(be) = &self.hot_be {
-            be.write_bytes(tpe, id, buf.clone()).await?;
+            if tpe != FileType::Config {
+                be.write_bytes(tpe, id, buf.clone()).await?;
+            }
         }
         self.be.write_bytes(tpe, id, buf).await
     }
diff --git a/src/commands/config.rs b/src/commands/config.rs
index 14ab687..c68d356 100644
--- a/src/commands/config.rs
+++ b/src/commands/config.rs
@@ -2,7 +2,7 @@ use anyhow::{bail, Result};
 use bytesize::ByteSize;
 use clap::Parser;
 
-use crate::backend::DecryptFullBackend;
+use crate::backend::{DecryptBackend, DecryptFullBackend, DecryptWriteBackend, WriteBackend};
 use crate::repo::ConfigFile;
 
 #[derive(Parser)]
@@ -13,13 +13,24 @@ pub(super) struct Opts {
 
 pub(super) async fn execute(
     be: &impl DecryptFullBackend,
+    hot_be: &Option<impl WriteBackend>,
     opts: Opts,
     config: ConfigFile,
 ) -> Result<()> {
     let mut new_config = config.clone();
     opts.config_opts.apply(&mut new_config)?;
     if new_config != config {
+        new_config.is_hot = None;
+        // for hot/cold backend, this only saves the config to the cold repo.
         be.save_file(&new_config).await?;
+
+        if let Some(hot_be) = hot_be {
+            // save config to hot repo
+            let dbe = DecryptBackend::new(hot_be, be.key().clone());
+            new_config.is_hot = Some(true);
+            dbe.save_file(&new_config).await?;
+        }
+
         println!("saved new config");
     } else {
         println!("config is unchanged");
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 40321d8..32ba57d 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -175,7 +175,7 @@ pub async fn execute() -> Result<()> {
 
     match cmd {
         Command::Backup(opts) => backup::execute(&dbe, opts, config, command).await?,
-        Command::Config(opts) => config::execute(&dbe, opts, config).await?,
+        Command::Config(opts) => config::execute(&dbe, &be_hot, opts, config).await?,
         Command::Cat(opts) => cat::execute(&dbe, opts).await?,
         Command::Check(opts) => check::execute(&dbe, &cache, &be_hot, &be, opts).await?,
         Command::Diff(opts) => diff::execute(&dbe, opts).await?,