diff --git a/libraries/AP_HAL_Linux/Scheduler.cpp b/libraries/AP_HAL_Linux/Scheduler.cpp
index 81ce9b5a646be..099637a6c7967 100644
--- a/libraries/AP_HAL_Linux/Scheduler.cpp
+++ b/libraries/AP_HAL_Linux/Scheduler.cpp
@@ -278,7 +278,7 @@ void Scheduler::register_timer_failsafe(AP_HAL::Proc failsafe, uint32_t period_u
 
 void Scheduler::suspend_timer_procs()
 {
-    if (!_timer_semaphore.take(0)) {
+    if (!_timer_semaphore.take(HAL_SEMAPHORE_BLOCK_FOREVER)) {
         printf("Failed to take timer semaphore\n");
     }
 }
@@ -297,7 +297,7 @@ void Scheduler::_timer_task()
     }
     _in_timer_proc = true;
 
-    if (!_timer_semaphore.take(0)) {
+    if (!_timer_semaphore.take(HAL_SEMAPHORE_BLOCK_FOREVER)) {
         printf("Failed to take timer semaphore in %s\n", __PRETTY_FUNCTION__);
     }
     // now call the timer based drivers
@@ -350,7 +350,7 @@ void Scheduler::_timer_task()
 
 void Scheduler::_run_io(void)
 {
-    if (!_io_semaphore.take(0)) {
+    if (!_io_semaphore.take(HAL_SEMAPHORE_BLOCK_FOREVER)) {
         return;
     }