diff --git a/cmd/imageproxy/main.go b/cmd/imageproxy/main.go
index 2c9ce5d8c..08d42b4e0 100644
--- a/cmd/imageproxy/main.go
+++ b/cmd/imageproxy/main.go
@@ -39,6 +39,7 @@ var referrers = flag.String("referrers", "", "comma separated list of allowed re
 var includeReferer = flag.Bool("includeReferer", false, "include referer header in remote requests")
 var followRedirects = flag.Bool("followRedirects", true, "follow redirects")
 var baseURL = flag.String("baseURL", "", "default base URL for relative remote URLs")
+var passRequestHeader = flag.String("passRequestHeader", "", "default authentication header")
 var cache tieredCache
 var signatureKeys signatureKeyList
 var scaleUp = flag.Bool("scaleUp", false, "allow images to scale beyond their original dimensions")
@@ -79,6 +80,7 @@ func main() {
 		}
 	}
 
+	p.DefaultPassRequestHeader = *passRequestHeader
 	p.IncludeReferer = *includeReferer
 	p.FollowRedirects = *followRedirects
 	p.Timeout = *timeout
diff --git a/imageproxy.go b/imageproxy.go
index 8a37a567f..8b48fb609 100644
--- a/imageproxy.go
+++ b/imageproxy.go
@@ -53,6 +53,10 @@ type Proxy struct {
 	// is included in remote requests.
 	IncludeReferer bool
 
+	// IncludeReferer controls whether the original Referer request header
+	// is included in remote requests.
+	DefaultPassRequestHeader string
+
 	// FollowRedirects controls whether imageproxy will follow redirects or not.
 	FollowRedirects bool
 
@@ -179,6 +183,9 @@ func (p *Proxy) serveImage(w http.ResponseWriter, r *http.Request) {
 		// pass along the referer header from the original request
 		copyHeader(actualReq.Header, r.Header, "referer")
 	}
+	if p.DefaultPassRequestHeader != "" {
+		actualReq.Header.Set(p.DefaultPassRequestHeader, r.Header.Get(p.DefaultPassRequestHeader))
+	}
 	if p.FollowRedirects {
 		// FollowRedirects is true (default), ensure that the redirected host is allowed
 		p.Client.CheckRedirect = func(newreq *http.Request, via []*http.Request) error {