diff --git a/src/constants.rs b/src/constants.rs
index cf8acbe..4a82a7f 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -11,11 +11,13 @@ pub const SUBCLASS_NONE: u8 = 0x0;
 
 #[repr(u8)]
 pub enum TransferMode {
-    // bulk transfers, optional interrupt IN
+    /// bulk transfers, optional interrupt IN
     Bulk = 0,
-    // control transfers, no interrupt IN
+    /// control transfers, no interrupt IN
+    #[allow(unused)]
     ControlA = 1,
-    // control transfers, optional interrupt IN
+    /// control transfers, optional interrupt IN
+    #[allow(unused)]
     ControlB = 2,
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 96eb92a..3ffbfb9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,8 +13,8 @@ extern crate delog;
 generate_macros!();
 
 pub mod class;
-pub mod constants;
-pub mod pipe;
+mod constants;
+mod pipe;
 pub mod types;
 
 // pub mod piv;
diff --git a/src/types.rs b/src/types.rs
index 5a8b350..2b12d2b 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,12 +1,12 @@
 use embedded_time::duration::Milliseconds;
 
 // pub mod apdu;
-pub mod packet;
+pub(crate) mod packet;
 
 // pub type MessageBuffer = apdu_dispatch::interchanges::Data;
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub enum ClassRequest {
+pub(crate) enum ClassRequest {
     Abort = 1,
     GetClockFrequencies = 2,
     GetDataRates = 3,