diff --git a/src/device/console.rs b/src/device/console.rs
index f0b23a7..4ce9d44 100644
--- a/src/device/console.rs
+++ b/src/device/console.rs
@@ -1,3 +1,6 @@
+use crate::device::Device;
+use crate::vm::Uxn;
+
 /**
  * The system console device
  *
@@ -11,7 +14,7 @@
  *
  */
 #[derive(Debug)]
-struct ConsoleDevice {
+pub struct ConsoleDevice {
     vector: u16,
     inbuffer: [u8; 256],
     inidx: usize,
diff --git a/src/device/null.rs b/src/device/null.rs
index 290b18d..e4eb58c 100644
--- a/src/device/null.rs
+++ b/src/device/null.rs
@@ -1,3 +1,6 @@
+use crate::device::Device;
+use crate::vm::Uxn;
+
 /**
  * The null device does nothing when reading or writing.
  */
diff --git a/src/device/system.rs b/src/device/system.rs
index f871813..d29418c 100644
--- a/src/device/system.rs
+++ b/src/device/system.rs
@@ -1,13 +1,16 @@
+use crate::device::Device;
+use crate::vm::Uxn;
+
 /**
  * The system device
  */
 #[derive(Debug)]
-struct SystemDevice {
+pub struct SystemDevice {
     buffer: [u8; 0xF],
 }
 
 impl SystemDevice {
-    fn new() -> SystemDevice {
+    pub fn new() -> SystemDevice {
         SystemDevice { buffer: [0; 0xF] }
     }
 }
diff --git a/src/vm.rs b/src/vm.rs
index e708a37..d1f48fc 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -2,6 +2,8 @@ use std::cell::RefCell;
 use std::rc::Rc;
 use std::*;
 
+use crate::device::null::NullDevice;
+use crate::device::system::SystemDevice;
 use crate::device::*;
 use crate::memory::*;
 use crate::stack::*;