diff --git a/macros/src/codegen/module.rs b/macros/src/codegen/module.rs
index afda26cf0c..22e08b9d46 100644
--- a/macros/src/codegen/module.rs
+++ b/macros/src/codegen/module.rs
@@ -290,7 +290,7 @@ pub fn codegen(
                         D::T: Into<<#app_path::#mono_type as rtic::time::Clock>::T>,
                 {
 
-                    let instant = if rtic::export::interrupt::free(|_| unsafe { #app_path::#m_ident.is_none() }) {
+                    let instant = if rtic::export::interrupt::free(|_| unsafe { #app_path::#m_ident.get_mut_unchecked().is_none() }) {
                         rtic::time::Instant::new(0)
                     } else {
                         #app_path::#m::now()
@@ -327,7 +327,7 @@ pub fn codegen(
                             };
 
                             rtic::export::interrupt::free(|_|
-                                if let Some(mono) = #app_path::#m_ident.as_mut() {
+                                if let Some(mono) = #app_path::#m_ident.get_mut_unchecked().as_mut() {
                                     #app_path::#tq.get_mut_unchecked().enqueue_unchecked(
                                         nr,
                                         || #enable_interrupt,
diff --git a/macros/src/codegen/timer_queue.rs b/macros/src/codegen/timer_queue.rs
index 47f45350e6..1d2a678e0d 100644
--- a/macros/src/codegen/timer_queue.rs
+++ b/macros/src/codegen/timer_queue.rs
@@ -76,7 +76,7 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
 
             items.push(quote!(
                 #[doc(hidden)]
-                static mut #mono: Option<#mono_type> = None;
+                static #mono: rtic::RacyCell<Option<#mono_type>> = rtic::RacyCell::new(None);
             ));
         }
 
@@ -128,7 +128,7 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
                 unsafe fn #bound_interrupt() {
 
                     while let Some((task, index)) = rtic::export::interrupt::free(|_|
-                        if let Some(mono) = #app_path::#m_ident.as_mut() {
+                        if let Some(mono) = #app_path::#m_ident.get_mut_unchecked().as_mut() {
                             #tq.get_mut_unchecked().dequeue(|| #disable_isr, mono)
                         } else {
                             // We can only use the timer queue if `init` has returned, and it
@@ -141,7 +141,7 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
                         }
                     }
 
-                    rtic::export::interrupt::free(|_| if let Some(mono) = #app_path::#m_ident.as_mut() {
+                    rtic::export::interrupt::free(|_| if let Some(mono) = #app_path::#m_ident.get_mut_unchecked().as_mut() {
                         mono.on_interrupt();
                     });
                 }