diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ec87a2..50f0cd2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## CHANGE LOG
 
+### v3.4.6
+
+- `Qiniu::RS.generate_download_token()` 方法的 `:pattern` 调整为必选项。
+
 ### v3.4.5
 
 - `Qiniu::RS.generate_upload_token()` 方法新增 `:callback_body` 和 `return_url` 选项。
diff --git a/docs/README.md b/docs/README.md
index 21d73f4..e6bd9ce 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -330,7 +330,7 @@ expires_in
 : 可选，数字类型，用于设置上传 URL 的有效期，单位：秒，缺省为 3600 秒，即 1 小时后该下载授权凭证（downloadToken）不再有效。
 
 pattern
-: 可选，字符串类型，用于设置可匹配的下载链接。参考：[downloadToken pattern 详解](http://docs.qiniutek.com/v3/api/io/#download-token-pattern)
+: 必选，字符串类型，用于设置可匹配的下载链接。参考：[downloadToken pattern 详解](http://docs.qiniutek.com/v3/api/io/#download-token-pattern)
 
 
 <a name="other-download-features"></a>
diff --git a/lib/qiniu/rs/version.rb b/lib/qiniu/rs/version.rb
index 39df71c..c74a1b0 100755
--- a/lib/qiniu/rs/version.rb
+++ b/lib/qiniu/rs/version.rb
@@ -5,7 +5,7 @@ module Qiniu
     module Version
       MAJOR = 3
       MINOR = 4
-      PATCH = 5
+      PATCH = 6
       # Returns a version string by joining <tt>MAJOR</tt>, <tt>MINOR</tt>, and <tt>PATCH</tt> with <tt>'.'</tt>
       #
       # Example
diff --git a/lib/qiniu/tokens/download_token.rb b/lib/qiniu/tokens/download_token.rb
index 4bc5906..f681520 100755
--- a/lib/qiniu/tokens/download_token.rb
+++ b/lib/qiniu/tokens/download_token.rb
@@ -13,7 +13,7 @@ module Qiniu
         attr_accessor :pattern, :expires_in
 
         def initialize(opts = {})
-          @pattern = opts[:pattern] || "*"
+          @pattern = opts[:pattern]
           @expires_in = opts[:expires_in] || 3600
         end