diff --git a/cpu/esp_common/freertos/task.c b/cpu/esp_common/freertos/task.c
index 5f0be2ecde..78920c7d24 100644
--- a/cpu/esp_common/freertos/task.c
+++ b/cpu/esp_common/freertos/task.c
@@ -103,6 +103,7 @@ BaseType_t xTaskCreate (TaskFunction_t pvTaskCode,
 
 void vTaskDelete (TaskHandle_t xTaskToDelete)
 {
+    extern volatile thread_t *sched_active_thread;
     DEBUG("%s pid=%d task=%p\n", __func__, thread_getpid(), xTaskToDelete);
 
     assert(xTaskToDelete != NULL);
diff --git a/cpu/esp_common/thread_arch.c b/cpu/esp_common/thread_arch.c
index d9929cff9c..cf304d2582 100644
--- a/cpu/esp_common/thread_arch.c
+++ b/cpu/esp_common/thread_arch.c
@@ -416,6 +416,8 @@ NORETURN void cpu_switch_context_exit(void)
  */
 NORETURN void task_exit(void)
 {
+    extern volatile thread_t *sched_active_thread;
+    extern volatile kernel_pid_t sched_active_pid;
     DEBUG("sched_task_exit: ending thread %" PRIkernel_pid "...\n",
           thread_getpid());