diff --git a/acme/internal/acme/acme.go b/acme/internal/acme/acme.go
index b6d7efb..effc0ec 100644
--- a/acme/internal/acme/acme.go
+++ b/acme/internal/acme/acme.go
@@ -229,14 +229,24 @@ func (c *Client) Register(a *Account, prompt func(tos string) bool) (*Account, e
 // GetReg retrieves an existing registration.
 // The url argument is an Account URI.
 func (c *Client) GetReg(url string) (*Account, error) {
-	a := &Account{URI: url}
-	return c.doReg(url, "reg", a)
+	a, err := c.doReg(url, "reg", nil)
+	if err != nil {
+		return nil, err
+	}
+	a.URI = url
+	return a, nil
 }
 
 // UpdateReg updates an existing registration.
 // It returns an updated account copy. The provided account is not modified.
 func (c *Client) UpdateReg(a *Account) (*Account, error) {
-	return c.doReg(a.URI, "reg", a)
+	uri := a.URI
+	a, err := c.doReg(uri, "reg", a)
+	if err != nil {
+		return nil, err
+	}
+	a.URI = uri
+	return a, nil
 }
 
 // Authorize performs the initial step in an authorization flow.
diff --git a/acme/internal/acme/acme_test.go b/acme/internal/acme/acme_test.go
index f8c1d53..3237b09 100644
--- a/acme/internal/acme/acme_test.go
+++ b/acme/internal/acme/acme_test.go
@@ -205,6 +205,9 @@ func TestUpdateReg(t *testing.T) {
 	if a.CurrentTerms != terms {
 		t.Errorf("a.CurrentTerms = %q; want %q", a.CurrentTerms, terms)
 	}
+	if a.URI != ts.URL {
+		t.Errorf("a.URI = %q; want %q", a.URI, ts.URL)
+	}
 }
 
 func TestGetReg(t *testing.T) {
@@ -266,6 +269,9 @@ func TestGetReg(t *testing.T) {
 	if a.CurrentTerms != newTerms {
 		t.Errorf("a.CurrentTerms = %q; want %q", a.CurrentTerms, newTerms)
 	}
+	if a.URI != ts.URL {
+		t.Errorf("a.URI = %q; want %q", a.URI, ts.URL)
+	}
 }
 
 func TestAuthorize(t *testing.T) {