diff --git a/Library/Homebrew/cask/url.rb b/Library/Homebrew/cask/url.rb
index c90cfc4898..dfd0ad23e5 100644
--- a/Library/Homebrew/cask/url.rb
+++ b/Library/Homebrew/cask/url.rb
@@ -32,7 +32,7 @@ module Cask
           trust_cert: T.nilable(T::Boolean),
           cookies:    T.nilable(T::Hash[String, String]),
           referer:    T.nilable(T.any(URI::Generic, String)),
-          header:     T.nilable(String),
+          header:     T.nilable(T.any(String, T::Array[String])),
           user_agent: T.nilable(T.any(Symbol, String)),
           data:       T.nilable(T::Hash[String, String]),
           only_path:  T.nilable(String),
@@ -57,6 +57,8 @@ module Cask
 
         @uri = URI(uri)
 
+        header = Array(header) unless header.nil?
+
         specs = {}
         specs[:verified]   = @verified   = verified
         specs[:using]      = @using      = using
@@ -67,7 +69,7 @@ module Cask
         specs[:trust_cert] = @trust_cert = trust_cert
         specs[:cookies]    = @cookies    = cookies
         specs[:referer]    = @referer    = referer
-        specs[:header]     = @header     = header
+        specs[:headers]    = @header     = header
         specs[:user_agent] = @user_agent = user_agent || :default
         specs[:data]       = @data       = data
         specs[:only_path]  = @only_path  = only_path
diff --git a/docs/Cask-Cookbook.md b/docs/Cask-Cookbook.md
index 4d8cf852d3..a1f67cc3f4 100644
--- a/docs/Cask-Cookbook.md
+++ b/docs/Cask-Cookbook.md
@@ -1079,7 +1079,7 @@ When a plain URL string is insufficient to fetch a file, additional information
 | `using:`           | the symbol `:post` is the only legal value
 | `cookies:`         | hash of cookies to be set in the download request
 | `referer:`         | string holding the URL to set as referer in the download request
-| `header:`          | string holding the header to set for the download request
+| `header:`          | string or array of strings holding the header(s) to set for the download request
 | `user_agent:`      | string holding the user agent to set for the download request. Can also be set to the symbol `:fake`, which will use a generic browser-like user agent string. We prefer `:fake` when the server does not require a specific user agent.
 | `data:`            | hash of parameters to be set in the POST request
 
@@ -1087,7 +1087,7 @@ Example of using `cookies:`: [oracle-jdk-javadoc.rb](https://github.com/Homebrew
 
 Example of using `referer:`: [firealpaca.rb](https://github.com/Homebrew/homebrew-cask/blob/37f434b99f51259e642793d65b7490540b71dc21/Casks/firealpaca.rb#L5-L6)
 
-Example of using `header:`: [issue-325182724](https://github.com/Homebrew/brew/pull/6545#issue-325182724)
+Example of using `header:`: [issue-325182724](https://github.com/Homebrew/brew/pull/6545#issue-325182724) [issue-15590](https://github.com/Homebrew/brew/issues/15590)
 
 #### When URL and Homepage Domains Differ, Add `verified:`