diff --git a/googleapi/googleapi.go b/googleapi/googleapi.go
index a520579e12d..65b125abd2c 100644
--- a/googleapi/googleapi.go
+++ b/googleapi/googleapi.go
@@ -79,8 +79,9 @@ type Error struct {
 	Header http.Header
 
 	Errors []ErrorItem
-	// Err is a wrapped apierror.APIError, typically derived from this Error.
-	Err error
+	// err is typically a wrapped apierror.APIError, see
+	// google-api-go-client/internal/gensupport/error.go.
+	err error
 }
 
 // ErrorItem is a detailed error code & message from the Google API frontend.
@@ -124,8 +125,13 @@ func (e *Error) Error() string {
 	return buf.String()
 }
 
+// Wrap allows an existing Error to wrap another error. See also [Error.Unwrap].
+func (e *Error) Wrap(err error) {
+	e.err = err
+}
+
 func (e *Error) Unwrap() error {
-	return e.Err
+	return e.err
 }
 
 type errorReply struct {
diff --git a/internal/gensupport/error.go b/internal/gensupport/error.go
index 339e4874d43..fa9d091930a 100644
--- a/internal/gensupport/error.go
+++ b/internal/gensupport/error.go
@@ -19,7 +19,7 @@ func WrapError(err error) error {
 	apiError, ok := apierror.ParseError(err, false)
 	var herr *googleapi.Error
 	if ok && errors.As(err, &herr) {
-		herr.Err = apiError
+		herr.Wrap(apiError)
 	}
 	return err
 }