diff --git a/Cargo.toml b/Cargo.toml
index 82295a3048..6b67c2a9e1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,7 +37,7 @@ required-features = ["timer-queue"]
 cortex-m = "0.5.8"
 cortex-m-rt = "0.6.7"
 cortex-m-rtfm-macros = { path = "macros", version = "0.4.0-beta.3" }
-heapless = "0.4.0"
+heapless = "0.4.1"
 owned-singleton = "0.1.0"
 
 [dev-dependencies]
diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 6b8e159416..71c6090723 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -1594,13 +1594,13 @@ fn pre_init(ctxt: &Context, app: &App, analysis: &Analysis) -> proc_macro2::Toke
     // these are `MaybeUninit` `ReadyQueue`s
     for dispatcher in ctxt.dispatchers.values() {
         let rq = &dispatcher.ready_queue;
-        exprs.push(quote!(#rq.set(rtfm::export::ReadyQueue::new());))
+        exprs.push(quote!(#rq.set(rtfm::export::ReadyQueue::new_sc());))
     }
 
     // these are `MaybeUninit` `FreeQueue`s
     for task in ctxt.tasks.values() {
         let fq = &task.free_queue;
-        exprs.push(quote!(#fq.set(rtfm::export::FreeQueue::new());))
+        exprs.push(quote!(#fq.set(rtfm::export::FreeQueue::new_sc());))
     }
 
     // end-of-FIXME
diff --git a/src/export.rs b/src/export.rs
index 200c69d95e..c1eeb87bac 100644
--- a/src/export.rs
+++ b/src/export.rs
@@ -12,13 +12,13 @@ pub use cortex_m::{
 };
 pub use cortex_m_rt::{entry, exception};
 pub use heapless::consts;
-use heapless::spsc::Queue;
+use heapless::spsc::{Queue, SingleCore};
 
 #[cfg(feature = "timer-queue")]
 pub use crate::tq::{isr as sys_tick, NotReady, TimerQueue};
 
-pub type FreeQueue<N> = Queue<u8, N>;
-pub type ReadyQueue<T, N> = Queue<(T, u8), N>;
+pub type FreeQueue<N> = Queue<u8, N, usize, SingleCore>;
+pub type ReadyQueue<T, N> = Queue<(T, u8), N, usize, SingleCore>;
 
 #[cfg(armv7m)]
 #[inline(always)]