diff --git a/drive/drive.go b/drive/drive.go
index c18deea30..2fafd5e1b 100644
--- a/drive/drive.go
+++ b/drive/drive.go
@@ -563,7 +563,7 @@ func (f *Fs) Put(in io.Reader, src fs.ObjectInfo) (fs.Object, error) {
 		// Make the API request to upload metadata and file data.
 		// Don't retry, return a retry error instead
 		err = f.pacer.CallNoRetry(func() (bool, error) {
-			info, err = f.svc.Files.Insert(createInfo).Media(in).Do()
+			info, err = f.svc.Files.Insert(createInfo).Media(in, googleapi.ContentType("")).Do()
 			return shouldRetry(err)
 		})
 		if err != nil {
@@ -1005,7 +1005,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) error {
 	if size == 0 || size < int64(driveUploadCutoff) {
 		// Don't retry, return a retry error instead
 		err = o.fs.pacer.CallNoRetry(func() (bool, error) {
-			info, err = o.fs.svc.Files.Update(updateInfo.Id, updateInfo).SetModifiedDate(true).Media(in).Do()
+			info, err = o.fs.svc.Files.Update(updateInfo.Id, updateInfo).SetModifiedDate(true).Media(in, googleapi.ContentType("")).Do()
 			return shouldRetry(err)
 		})
 		if err != nil {
diff --git a/googlecloudstorage/googlecloudstorage.go b/googlecloudstorage/googlecloudstorage.go
index f02ff381b..99230c1c4 100644
--- a/googlecloudstorage/googlecloudstorage.go
+++ b/googlecloudstorage/googlecloudstorage.go
@@ -690,7 +690,7 @@ func (o *Object) Update(in io.Reader, src fs.ObjectInfo) error {
 		Updated:     modTime.Format(timeFormatOut), // Doesn't get set
 		Metadata:    metadataFromModTime(modTime),
 	}
-	newObject, err := o.fs.svc.Objects.Insert(o.fs.bucket, &object).Media(in).Name(object.Name).PredefinedAcl(o.fs.objectAcl).Do()
+	newObject, err := o.fs.svc.Objects.Insert(o.fs.bucket, &object).Media(in, googleapi.ContentType("")).Name(object.Name).PredefinedAcl(o.fs.objectAcl).Do()
 	if err != nil {
 		return err
 	}