diff --git a/histfilesize/.bashrc b/histfilesize/.bashrc
deleted file mode 100644
index fb52921..0000000
--- a/histfilesize/.bashrc
+++ /dev/null
@@ -1 +0,0 @@
-HISTFILESIZE=16777215
diff --git a/histfilesize/README.md b/histfilesize/README.md
deleted file mode 100644
index 8fa36dd..0000000
--- a/histfilesize/README.md
+++ /dev/null
@@ -1,22 +0,0 @@
-# Bash `HISTFILESIZE` の限界
-
-```console
-$ seq 0 $((0x7fffffff)) > .bash_history
-$ wc -l .bash_history
-2147483648 .bash_history
-$ echo $((0x7fffffff))
-2147483647
-$ docker compose run --rm bash
-root@ff1161946537:/# 225859065
-$ wc -l .bash_history
-16777215 .bash_history
-```
-
-- 225859066 行 (< 0x7fffffff bytes) まで読み込まれた
-  - `HISTFILESIZE=$((0x7fffffff))` 以上にするのは意味がない
-- `HISTFILESIZE=$((0x7fffff))` 行に切り落とせる
-- `HISTFILESIZE=$((0xffffff))` 行に切り落とせる
-- `HISTFILESIZE=$((0x7fffffff))` では .bash_history が大きいとハングすることがあった
-  - このあたりが限界だろう
-  - 0xffffff 行くらいまでならおそらく OK だろう
-  - ちなみに `HISTFILESIZE=-1` はどうかというと、これも .bash_history が大きいとハングした
diff --git a/histfilesize/compose.yml b/histfilesize/compose.yml
deleted file mode 100644
index 5370a1b..0000000
--- a/histfilesize/compose.yml
+++ /dev/null
@@ -1,5 +0,0 @@
-services:
-  bash:
-    image: ubuntu:jammy
-    volumes:
-      - "./:/root"