diff --git a/Cargo.toml b/Cargo.toml
index bd49d23..8cf925a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,7 @@ panic-halt = "0.2.0"
 # panic-itm = "0.4.1"
 
 # Uncomment for the allocator example.
-# alloc-cortex-m = "0.3.5"
+# alloc-cortex-m = "0.4.0"
 
 # Uncomment for the device example.
 # Update `memory.x`, set target to `thumbv7em-none-eabihf` in `.cargo/config`,
diff --git a/examples/allocator.rs b/examples/allocator.rs
index 6edc48a..53c3023 100644
--- a/examples/allocator.rs
+++ b/examples/allocator.rs
@@ -9,7 +9,6 @@
 //!
 //! ---
 
-#![feature(alloc)]
 #![feature(alloc_error_handler)]
 #![no_main]
 #![no_std]
@@ -23,7 +22,7 @@ use core::alloc::Layout;
 use alloc_cortex_m::CortexMHeap;
 use cortex_m::asm;
 use cortex_m_rt::entry;
-use cortex_m_semihosting::hprintln;
+use cortex_m_semihosting::{hprintln, debug};
 
 // this is the allocator the application will use
 #[global_allocator]