diff --git a/sim/mcuboot-sys/Cargo.toml b/sim/mcuboot-sys/Cargo.toml
index 9c39326..79a2663 100644
--- a/sim/mcuboot-sys/Cargo.toml
+++ b/sim/mcuboot-sys/Cargo.toml
@@ -39,7 +39,7 @@
 [dependencies]
 lazy_static = "1.2"
 libc = "0.2.0"
-log = "0.3"
+log = "0.4"
 simflash = { path = "../simflash" }
 
 # Optimize some, even when building for debugging, otherwise the tests
diff --git a/sim/mcuboot-sys/src/api.rs b/sim/mcuboot-sys/src/api.rs
index 3914b22..78a1bbd 100644
--- a/sim/mcuboot-sys/src/api.rs
+++ b/sim/mcuboot-sys/src/api.rs
@@ -1,13 +1,16 @@
 //! HAL api for MyNewt applications
 
 use simflash::{Result, Flash, FlashPtr};
+use lazy_static::lazy_static;
 use libc;
-use log::LogLevel;
-use std::mem;
-use std::slice;
-use std::collections::HashMap;
-use std::sync::Mutex;
-use std::ops::Deref;
+use log::{Level, log_enabled, warn};
+use std::{
+    collections::HashMap,
+    mem,
+    ops::Deref,
+    slice,
+    sync::Mutex,
+};
 
 /// A FlashMap maintain a table of [device_id -> Flash trait]
 pub type FlashMap = HashMap<u8, FlashPtr>;
@@ -30,16 +33,16 @@
 }
 
 // Set the flash device to be used by the simulation.  The pointer is unsafely stashed away.
-pub unsafe fn set_flash(dev_id: u8, dev: &mut Flash) {
+pub unsafe fn set_flash(dev_id: u8, dev: &mut dyn Flash) {
     let mut flash_params = FLASH_PARAMS.lock().unwrap();
     flash_params.insert(dev_id, FlashParams {
         align: dev.align() as u8,
         erased_val: dev.erased_val(),
     });
 
-    let dev: &'static mut Flash = mem::transmute(dev);
+    let dev: &'static mut dyn Flash = mem::transmute(dev);
     let mut flash = FLASH.lock().unwrap();
-    flash.insert(dev_id, FlashPtr{ptr: dev as *mut Flash});
+    flash.insert(dev_id, FlashPtr{ptr: dev as *mut dyn Flash});
 }
 
 pub unsafe fn clear_flash(dev_id: u8) {
@@ -117,10 +120,10 @@
 #[no_mangle]
 pub extern fn sim_log_enabled(level: libc::c_int) -> libc::c_int {
     let res = match level {
-        1 => log_enabled!(LogLevel::Error),
-        2 => log_enabled!(LogLevel::Warn),
-        3 => log_enabled!(LogLevel::Info),
-        4 => log_enabled!(LogLevel::Trace),
+        1 => log_enabled!(Level::Error),
+        2 => log_enabled!(Level::Warn),
+        3 => log_enabled!(Level::Info),
+        4 => log_enabled!(Level::Trace),
         _ => false,
     };
     if res {
diff --git a/sim/mcuboot-sys/src/c.rs b/sim/mcuboot-sys/src/c.rs
index dc73134..d623ef9 100644
--- a/sim/mcuboot-sys/src/c.rs
+++ b/sim/mcuboot-sys/src/c.rs
@@ -2,6 +2,7 @@
 
 use crate::area::AreaDesc;
 use simflash::SimFlashMap;
+use lazy_static::lazy_static;
 use libc;
 use crate::api;
 use std::sync::Mutex;
diff --git a/sim/mcuboot-sys/src/lib.rs b/sim/mcuboot-sys/src/lib.rs
index 9f5c850..351666e 100644
--- a/sim/mcuboot-sys/src/lib.rs
+++ b/sim/mcuboot-sys/src/lib.rs
@@ -1,8 +1,3 @@
-#[macro_use] extern crate lazy_static;
-extern crate libc;
-#[macro_use] extern crate log;
-extern crate simflash;
-
 mod area;
 pub mod c;