diff --git a/04_mailboxes/src/mbox.rs b/04_mailboxes/src/mbox.rs
index 75465290..fd9ab0e9 100644
--- a/04_mailboxes/src/mbox.rs
+++ b/04_mailboxes/src/mbox.rs
@@ -25,11 +25,11 @@
 use super::MMIO_BASE;
 use volatile_register::{RO, WO};
 
-pub const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
+const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
 
 #[allow(non_snake_case)]
 #[repr(C)]
-pub struct Registers {
+struct Registers {
     READ: RO<u32>,          // 0x00
     __reserved_0: [u32; 3], // 0x04
     POLL: RO<u32>,          // 0x10
diff --git a/05_uart0/src/mbox.rs b/05_uart0/src/mbox.rs
index 89ce15ae..fe4e8f76 100644
--- a/05_uart0/src/mbox.rs
+++ b/05_uart0/src/mbox.rs
@@ -25,11 +25,11 @@
 use super::MMIO_BASE;
 use volatile_register::{RO, WO};
 
-pub const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
+const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
 
 #[allow(non_snake_case)]
 #[repr(C)]
-pub struct Registers {
+struct Registers {
     READ: RO<u32>,          // 0x00
     __reserved_0: [u32; 3], // 0x04
     POLL: RO<u32>,          // 0x10
diff --git a/06_random/src/mbox.rs b/06_random/src/mbox.rs
index cfa4bfcc..ab38c1e5 100644
--- a/06_random/src/mbox.rs
+++ b/06_random/src/mbox.rs
@@ -25,11 +25,11 @@
 use super::MMIO_BASE;
 use volatile_register::{RO, WO};
 
-pub const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
+const VIDEOCORE_MBOX: u32 = MMIO_BASE + 0xB880;
 
 #[allow(non_snake_case)]
 #[repr(C)]
-pub struct Registers {
+struct Registers {
     READ: RO<u32>,          // 0x00
     __reserved_0: [u32; 3], // 0x04
     POLL: RO<u32>,          // 0x10
diff --git a/06_random/src/rand.rs b/06_random/src/rand.rs
index 8c3f3193..40cfbabb 100644
--- a/06_random/src/rand.rs
+++ b/06_random/src/rand.rs
@@ -25,7 +25,7 @@
 use super::MMIO_BASE;
 use volatile_register::*;
 
-pub const RNG_BASE: u32 = MMIO_BASE + 0x104_000;
+const RNG_BASE: u32 = MMIO_BASE + 0x104_000;
 
 #[allow(non_snake_case)]
 #[repr(C)]