diff --git a/cryptor/crypt_util.go b/cryptor/crypto_internal.go
similarity index 100%
rename from cryptor/crypt_util.go
rename to cryptor/crypto_internal.go
diff --git a/docs/function.md b/docs/function.md
index c05ad53..8ca3d9a 100644
--- a/docs/function.md
+++ b/docs/function.md
@@ -26,7 +26,6 @@ import (
 - [Compose](#Compose)
 - [Debounced](#Debounced)
 - [Delay](#Delay)
-- [Delay](#Delay)
 - [Watcher](#Watcher)
 
 <div STYLE="page-break-after: always;"></div>
diff --git a/docs/function_zh-CN.md b/docs/function_zh-CN.md
index 6331be8..8fdfaaa 100644
--- a/docs/function_zh-CN.md
+++ b/docs/function_zh-CN.md
@@ -26,7 +26,6 @@ import (
 - [Compose](#Compose)
 - [Debounced](#Debounced)
 - [Delay](#Delay)
-- [Delay](#Delay)
 - [Watcher](#Watcher)
 
 <div STYLE="page-break-after: always;"></div>
diff --git a/formatter/formatter_util.go b/formatter/formatter_internal.go
similarity index 100%
rename from formatter/formatter_util.go
rename to formatter/formatter_internal.go
diff --git a/function/function_util.go b/function/function_internal.go
similarity index 100%
rename from function/function_util.go
rename to function/function_internal.go
diff --git a/netutil/http_util.go b/netutil/net_internal.go
similarity index 100%
rename from netutil/http_util.go
rename to netutil/net_internal.go
diff --git a/slice/slice_util.go b/slice/slice_internal.go
similarity index 100%
rename from slice/slice_util.go
rename to slice/slice_internal.go
diff --git a/strutil/string_util.go b/strutil/string_internal.go
similarity index 100%
rename from strutil/string_util.go
rename to strutil/string_internal.go