diff --git a/eml.go b/eml.go
index 844a5ad..ed20d0d 100644
--- a/eml.go
+++ b/eml.go
@@ -405,7 +405,7 @@ func parseEMLAttachmentEmbed(contentDisposition []string, multiPart *multipart.P
 		}
 	case "inline":
 		if contentID, _ := parseMultiPartHeader(multiPart.Header.Get(HeaderContentID.String())); contentID != "" {
-			if err := msg.EmbedReader(filename, dataReader, WithContentID(contentID)); err != nil {
+			if err := msg.EmbedReader(filename, dataReader, WithFileContentID(contentID)); err != nil {
 				return fmt.Errorf("failed to embed multipart body: %w", err)
 			}
 			return nil
diff --git a/file.go b/file.go
index a759b3d..45e142a 100644
--- a/file.go
+++ b/file.go
@@ -22,8 +22,8 @@ type File struct {
 	Writer      func(w io.Writer) (int64, error)
 }
 
-// WithContentID sets the Content-ID header for the File
-func WithContentID(id string) FileOption {
+// WithFileContentID sets the Content-ID header for the File
+func WithFileContentID(id string) FileOption {
 	return func(f *File) {
 		f.Header.Set(HeaderContentID.String(), id)
 	}