diff --git a/Library/Homebrew/download_strategy.rb b/Library/Homebrew/download_strategy.rb
index 2a8b6e5859..adeb0a02ad 100644
--- a/Library/Homebrew/download_strategy.rb
+++ b/Library/Homebrew/download_strategy.rb
@@ -381,7 +381,7 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
   # Curl options to be always passed to curl,
   # with raw head calls (`curl --head`) or with actual `fetch`.
   def _curl_opts
-    return ["--user" << meta.fetch(:user)] if meta.key?(:user)
+    return ["--user", meta.fetch(:user)] if meta.key?(:user)
     []
   end
 
diff --git a/Library/Homebrew/test/download_strategies_spec.rb b/Library/Homebrew/test/download_strategies_spec.rb
index 8c376a6493..06d6fa855c 100644
--- a/Library/Homebrew/test/download_strategies_spec.rb
+++ b/Library/Homebrew/test/download_strategies_spec.rb
@@ -200,6 +200,17 @@ describe GitDownloadStrategy do
   end
 end
 
+describe CurlDownloadStrategy do
+  subject { described_class.new(name, resource) }
+  let(:name) { "foo" }
+  let(:url) { "http://example.com/foo.tar.gz" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: { user: "download:123456" }, version: nil) }
+
+  it "parses the opts and sets the corresponding args" do
+    expect(subject.send(:_curl_opts)).to eq(["--user", "download:123456"])
+  end
+end
+
 describe DownloadStrategyDetector do
   describe "::detect" do
     subject { described_class.detect(url) }