diff --git a/fs/fserrors/error.go b/fs/fserrors/error.go
index eb6d7055d..aef83fe35 100644
--- a/fs/fserrors/error.go
+++ b/fs/fserrors/error.go
@@ -236,14 +236,14 @@ func IsRetryAfterError(err error) bool {
 func Cause(cause error) (retriable bool, err error) {
 	errors.Walk(cause, func(c error) bool {
 		// Check for net error Timeout()
-		if x, ok := err.(interface {
+		if x, ok := c.(interface {
 			Timeout() bool
 		}); ok && x.Timeout() {
 			retriable = true
 		}
 
 		// Check for net error Temporary()
-		if x, ok := err.(interface {
+		if x, ok := c.(interface {
 			Temporary() bool
 		}); ok && x.Temporary() {
 			retriable = true
diff --git a/fs/fserrors/error_test.go b/fs/fserrors/error_test.go
index 93ffcaa67..f153c7aab 100644
--- a/fs/fserrors/error_test.go
+++ b/fs/fserrors/error_test.go
@@ -62,6 +62,12 @@ type myError4 struct {
 
 func (e *myError4) Error() string { return e.e.Error() }
 
+type myError5 struct{}
+
+func (e *myError5) Error() string { return "" }
+
+func (e *myError5) Temporary() bool { return true }
+
 type errorCause struct {
 	e error
 }
@@ -73,6 +79,7 @@ func (e *errorCause) Cause() error { return e.e }
 func TestCause(t *testing.T) {
 	e3 := &myError3{3}
 	e4 := &myError4{io.EOF}
+	e5 := &myError5{}
 	eNil1 := &myError2{nil}
 	eNil2 := &myError2{Err: (*myError2)(nil)}
 	errPotato := errors.New("potato")
@@ -97,6 +104,7 @@ func TestCause(t *testing.T) {
 		{&myError2{io.EOF}, false, io.EOF},
 		{e3, false, e3},
 		{e4, false, e4},
+		{e5, true, e5},
 		{&errorCause{errPotato}, false, errPotato},
 		{nilCause1, false, nilCause1},
 		{nilCause2, false, nilCause2.e},