diff --git a/nyx/auxiliary_buffer.c b/nyx/auxiliary_buffer.c
index 7ba076de3e..afbe400531 100644
--- a/nyx/auxiliary_buffer.c
+++ b/nyx/auxiliary_buffer.c
@@ -187,7 +187,7 @@ void set_pt_overflow_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer)
   VOLATILE_WRITE_8(auxilary_buffer->result.pt_overflow, 1);
 }
 
-void set_exec_done_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer, uint8_t sec, uint32_t usec, uint32_t num_dirty_pages){
+void set_exec_done_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer, uint32_t sec, uint32_t usec, uint32_t num_dirty_pages){
   VOLATILE_WRITE_8(auxilary_buffer->result.exec_done, 1);
 
   VOLATILE_WRITE_32(auxilary_buffer->result.runtime_sec, sec);
diff --git a/nyx/auxiliary_buffer.h b/nyx/auxiliary_buffer.h
index 0ac87ce8c2..90dda2f31c 100644
--- a/nyx/auxiliary_buffer.h
+++ b/nyx/auxiliary_buffer.h
@@ -155,7 +155,7 @@ void set_asan_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer);
 void set_timeout_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer);
 void set_reload_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer);
 void set_pt_overflow_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer);
-void set_exec_done_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer, uint8_t sec, uint32_t usec, uint32_t num_dirty_pages);
+void set_exec_done_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer, uint32_t sec, uint32_t usec, uint32_t num_dirty_pages);
 void set_state_auxiliary_result_buffer(auxilary_buffer_t* auxilary_buffer, uint8_t state);
 void set_hprintf_auxiliary_buffer(auxilary_buffer_t* auxilary_buffer, char* msg, uint32_t len);
 
diff --git a/nyx/synchronization.c b/nyx/synchronization.c
index c502f89138..8aa1ade89a 100644
--- a/nyx/synchronization.c
+++ b/nyx/synchronization.c
@@ -245,15 +245,26 @@ void synchronization_lock_hprintf(void){
 }
 void synchronization_lock(void){
 
+	timeout_detector_t timer = GET_GLOBAL_STATE()->timeout_detector;
 	pthread_mutex_lock(&synchronization_lock_mutex);
 	run_counter++;
 
 	if(qemu_get_cpu(0)->intel_pt_run_trashed){
 		set_pt_overflow_auxiliary_result_buffer(GET_GLOBAL_STATE()->auxilary_buffer);
 	}
+
+	long runtime_sec = timer.config.tv_sec - timer.alarm.it_value.tv_sec;
+	long runtime_usec = timer.config.tv_usec - timer.alarm.it_value.tv_usec;
+
+	if (runtime_usec < 0) {
+		if (runtime_sec < 1) {
+			fprintf(stderr, "Error: negative payload runtime?!\n");
+		}
+		runtime_sec -= 1;
+		runtime_usec = timer.config.tv_usec - timer.alarm.it_value.tv_usec + 1000000;
+	}
 	set_exec_done_auxiliary_result_buffer(GET_GLOBAL_STATE()->auxilary_buffer,
-											GET_GLOBAL_STATE()->timeout_detector.timeout_sec - GET_GLOBAL_STATE()->timeout_detector.arm_timeout.it_value.tv_sec,
-											GET_GLOBAL_STATE()->timeout_detector.timeout_usec - (uint32_t)GET_GLOBAL_STATE()->timeout_detector.arm_timeout.it_value.tv_usec,
+                                            runtime_sec, runtime_usec,
 											GET_GLOBAL_STATE()->num_dirty_pages);
 	/*
 	if(last_timeout){