@@ -69,8 +69,10 @@ func getUserAgentFromContext(ctx context.Context) string {

 	return upstreamUA

 }

+const charsToEscape = `();\`

+

 // escapeStr returns s with every rune in charsToEscape escaped by a backslash

-func escapeStr(s string, charsToEscape string) string {

+func escapeStr(s string) string {

 	var ret string

 	for _, currRune := range s {

 		appended := false

@@ -93,7 +95,5 @@ func escapeStr(s string, charsToEscape string) string {

 //

 //	$dockerUA UpstreamClient($upstreamUA)

 func insertUpstreamUserAgent(upstreamUA string, dockerUA string) string {

-	charsToEscape := `();\`

-	upstreamUAEscaped := escapeStr(upstreamUA, charsToEscape)

-	return fmt.Sprintf("%s UpstreamClient(%s)", dockerUA, upstreamUAEscaped)

+	return fmt.Sprintf("%s UpstreamClient(%s)", dockerUA, escapeStr(upstreamUA))

 }