diff --git a/target/sim/sw/device/apps/libomptarget_device/src/sw_mailbox.c b/target/sim/sw/device/apps/libomptarget_device/src/sw_mailbox.c
index eec8161f2..f3b265b9c 100644
--- a/target/sim/sw/device/apps/libomptarget_device/src/sw_mailbox.c
+++ b/target/sim/sw/device/apps/libomptarget_device/src/sw_mailbox.c
@@ -25,10 +25,6 @@ volatile struct ring_buf *g_h2a_mbox;
 /***********************************************************************************
  * FUNCTIONS
  ***********************************************************************************/
-__attribute__((optimize("O0"))) void csleep(uint32_t cycles) {
-    uint32_t start = snrt_mcycle();
-    while ((snrt_mcycle() - start) < cycles) {}
-}
 
 int syscall(uint64_t which, uint64_t arg0, uint64_t arg1, uint64_t arg2,
             uint64_t arg3, uint64_t arg4) {