diff --git a/registry/api/errcode/register.go b/registry/api/errcode/register.go
index 7489e84f..71cf6f7a 100644
--- a/registry/api/errcode/register.go
+++ b/registry/api/errcode/register.go
@@ -71,10 +71,7 @@ var (
 		Message: "too many requests",
 		Description: `Returned when a client attempts to contact a
 		service too many times`,
-		// FIXME: go1.5 doesn't export http.StatusTooManyRequests while
-		// go1.6 does. Update the hardcoded value to the constant once
-		// Docker updates golang version to 1.6.
-		HTTPStatusCode: 429,
+		HTTPStatusCode: http.StatusTooManyRequests,
 	})
 )
 
diff --git a/registry/client/errors.go b/registry/client/errors.go
index adbaacf4..804e69e0 100644
--- a/registry/client/errors.go
+++ b/registry/client/errors.go
@@ -54,10 +54,7 @@ func parseHTTPErrorResponse(statusCode int, r io.Reader) error {
 		switch statusCode {
 		case http.StatusUnauthorized:
 			return errcode.ErrorCodeUnauthorized.WithMessage(detailsErr.Details)
-		// FIXME: go1.5 doesn't export http.StatusTooManyRequests while
-		// go1.6 does. Update the hardcoded value to the constant once
-		// Docker updates golang version to 1.6.
-		case 429:
+		case http.StatusTooManyRequests:
 			return errcode.ErrorCodeTooManyRequests.WithMessage(detailsErr.Details)
 		default:
 			return errcode.ErrorCodeUnknown.WithMessage(detailsErr.Details)