diff --git a/rustmeter-beacon/rustmeter-beacon-core/src/protocol/raw_writers.rs b/rustmeter-beacon/rustmeter-beacon-core/src/protocol/raw_writers.rs
index d2e3ff1..5a32164 100644
--- a/rustmeter-beacon/rustmeter-beacon-core/src/protocol/raw_writers.rs
+++ b/rustmeter-beacon/rustmeter-beacon-core/src/protocol/raw_writers.rs
@@ -23,7 +23,7 @@ pub fn write_embassy_task_ready(task_id: u16, executor_id: u3) {
     buffer[1..3].copy_from_slice(&task_id.to_le_bytes());
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[3..]);
     unsafe { write_tracing_data(&buffer[..3 + pos]) };
 }
@@ -36,7 +36,7 @@ pub fn write_embassy_task_exec_begin(task_id: u16, executor_id: u3) {
     buffer[1..3].copy_from_slice(&task_id.to_le_bytes());
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[3..]);
     unsafe { write_tracing_data(&buffer[..3 + pos]) };
 }
@@ -48,7 +48,7 @@ pub fn write_embassy_task_exec_end(executor_id: u3) {
     buffer[0] = (event_ids::EMBASSY_TASK_EXEC_END << 3) | executor_id.as_u8();
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[1..]);
     unsafe { write_tracing_data(&buffer[..1 + pos]) };
 }
@@ -60,7 +60,7 @@ pub fn write_embassy_executor_poll_start(executor_id: u3) {
     buffer[0] = (event_ids::EMBASSY_EXECUTOR_POLL_START << 3) | executor_id.as_u8();
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[1..]);
     unsafe { write_tracing_data(&buffer[..1 + pos]) };
 }
@@ -72,7 +72,7 @@ pub fn write_embassy_executor_idle(executor_id: u3) {
     buffer[0] = (event_ids::EMBASSY_EXECUTOR_IDLE << 3) | executor_id.as_u8();
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[1..]);
     unsafe { write_tracing_data(&buffer[..1 + pos]) };
 }
@@ -85,7 +85,7 @@ pub fn write_monitor_start(monitor_id: u8) {
     buffer[1] = monitor_id;
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[2..]);
     unsafe { write_tracing_data(&buffer[..2 + pos]) };
 }
@@ -97,7 +97,7 @@ pub fn write_monitor_end() {
     buffer[0] = event_ids::MONITOR_END << 3;
 
     // Write to global buffer
-    let timestamp = TimeDelta::from_now();
+    let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
     let pos = timestamp.write_bytes_mut(&mut buffer[1..]);
     unsafe { write_tracing_data(&buffer[..1 + pos]) };
 }
@@ -120,7 +120,7 @@ pub fn write_defmt_data(data: &[u8]) {
         let next_pos = 2 + chunk_size;
 
         // Write to global buffer with timestamp
-        let timestamp = TimeDelta::from_now();
+        let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
         let pos = timestamp.write_bytes_mut(&mut buffer[next_pos..]);
         unsafe { write_tracing_data(&buffer[..next_pos + pos]) };
 
diff --git a/rustmeter-beacon/rustmeter-beacon-core/src/time_delta.rs b/rustmeter-beacon/rustmeter-beacon-core/src/time_delta.rs
index 3966501..f74a22a 100644
--- a/rustmeter-beacon/rustmeter-beacon-core/src/time_delta.rs
+++ b/rustmeter-beacon/rustmeter-beacon-core/src/time_delta.rs
@@ -1,5 +1,6 @@
 #![allow(unused)] // in test mode, things might be unused
 use arbitrary_int::traits::Integer;
+use critical_section::CriticalSection;
 
 use crate::{
     buffer::{BufferReader, BufferWriter},
@@ -85,7 +86,7 @@ impl TimeDelta {
     /// This has to be called inside a critical section
     #[inline(always)]
     #[cfg(not(test))]
-    pub fn from_now() -> Self {
+    pub fn from_now<'cs>(_cs: CriticalSection<'cs>) -> Self {
         let core_id = unsafe { crate::get_current_core_id() as usize };
         if !CORE_CLOCK_REFERENCED[core_id].load(portable_atomic::Ordering::Relaxed) {
             do_core_clock_referencing(core_id);
@@ -107,7 +108,7 @@ impl TimeDelta {
     }
 
     #[cfg(test)]
-    pub fn from_now() -> Self {
+    pub fn from_now<'cs>(_cs: CriticalSection<'cs>) -> Self {
         let now = unsafe { get_tracing_raw_ticks() };
         TimeDelta { delta: now }
     }
diff --git a/rustmeter-beacon/rustmeter-beacon-core/src/tracing.rs b/rustmeter-beacon/rustmeter-beacon-core/src/tracing.rs
index cfb31dd..6eecada 100644
--- a/rustmeter-beacon/rustmeter-beacon-core/src/tracing.rs
+++ b/rustmeter-beacon/rustmeter-beacon-core/src/tracing.rs
@@ -19,7 +19,7 @@ pub fn write_tracing_event(event: EventPayload) {
     critical_section::with(|cs| {
         let _lock = TRACE_WRITING.borrow(cs);
 
-        let timestamp = TimeDelta::from_now();
+        let timestamp = TimeDelta::from_now(cs);
 
         // Write event data
         let mut buffer = BufferWriter::new();
diff --git a/rustmeter-beacon/rustmeter-beacon-target/src/cortex/tracing_rtt.rs b/rustmeter-beacon/rustmeter-beacon-target/src/cortex/tracing_rtt.rs
index 833f655..2a7db8f 100644
--- a/rustmeter-beacon/rustmeter-beacon-target/src/cortex/tracing_rtt.rs
+++ b/rustmeter-beacon/rustmeter-beacon-target/src/cortex/tracing_rtt.rs
@@ -12,7 +12,7 @@ fn write_tracing_data(data: &[u8]) {
     let idx = if core_id > 1 { 0 } else { core_id as usize };
 
     // Write to Buffer
-    cortex_m::interrupt::free(|_| {
+    critical_section::with(|cs| {
         // Check for dropped events
         let dropped_events = unsafe { DROPPED_EVENTS_COUNTER[idx] };
         if dropped_events > 0 {
@@ -20,7 +20,7 @@ fn write_tracing_data(data: &[u8]) {
             let mut buffer = [0u8; 12];
             buffer[0] = event_ids::DATA_LOSS_EVENT << 3;
             buffer[1..5].copy_from_slice(&dropped_events.to_le_bytes());
-            let timestamp = TimeDelta::from_now();
+            let timestamp = TimeDelta::from_now(cs);
             let pos = timestamp.write_bytes_mut(&mut buffer[5..]);
 
             // Try to write dropped events data
diff --git a/rustmeter-beacon/rustmeter-beacon-target/src/espressif/tracing_esp.rs b/rustmeter-beacon/rustmeter-beacon-target/src/espressif/tracing_esp.rs
index 4ebdd17..208bf64 100644
--- a/rustmeter-beacon/rustmeter-beacon-target/src/espressif/tracing_esp.rs
+++ b/rustmeter-beacon/rustmeter-beacon-target/src/espressif/tracing_esp.rs
@@ -62,7 +62,7 @@ fn write_tracing_data(data: &[u8]) {
         let mut buffer = [0u8; 12];
         buffer[0] = event_ids::DATA_LOSS_EVENT << 3;
         buffer[1..5].copy_from_slice(&dropped_events.to_le_bytes());
-        let timestamp = TimeDelta::from_now();
+        let timestamp = critical_section::with(|cs| TimeDelta::from_now(cs));
         let pos = timestamp.write_bytes_mut(&mut buffer[5..]);
 
         // Try to write dropped events data