diff --git a/include/fluent-bit/flb_scheduler.h b/include/fluent-bit/flb_scheduler.h
index 11b526d350f..227d8a5a337 100644
--- a/include/fluent-bit/flb_scheduler.h
+++ b/include/fluent-bit/flb_scheduler.h
@@ -192,11 +192,14 @@ struct flb_sched_timer_coro {
     struct cfl_list _head;
 };
 
+#define FLB_SCHED_TLS_MAGIC 0x53544350u
+
 /* parameter for timer callback running under a co-routine */
 struct flb_sched_timer_coro_cb_params {
     struct flb_sched_timer_coro *stc;
     struct flb_config *config;
     void *data;
+    uint32_t magic;
     struct flb_coro *coro;
 };
 
@@ -259,6 +262,7 @@ static FLB_INLINE void sched_timer_cb_params_set(struct flb_sched_timer_coro *st
     params->config = config;
     params->data = data;
     params->coro = coro;
+    params->magic = FLB_SCHED_TLS_MAGIC;
 
     FLB_TLS_SET(sched_timer_coro_cb_params, params);
     co_switch(coro->callee);
diff --git a/src/flb_engine.c b/src/flb_engine.c
index d7fcd7a6223..6ab1b7d0374 100644
--- a/src/flb_engine.c
+++ b/src/flb_engine.c
@@ -1228,7 +1228,7 @@ int flb_engine_shutdown(struct flb_config *config)
 
     /* scheduler */
     sched_params = (struct flb_sched_timer_coro_cb_params *) FLB_TLS_GET(sched_timer_coro_cb_params);
-    if (sched_params != NULL) {
+    if (sched_params && sched_params->magic == FLB_SCHED_TLS_MAGIC) {
         flb_free(sched_params);
         FLB_TLS_SET(sched_timer_coro_cb_params, NULL);
     }
diff --git a/src/flb_output_thread.c b/src/flb_output_thread.c
index bb146665b0c..56b38967775 100644
--- a/src/flb_output_thread.c
+++ b/src/flb_output_thread.c
@@ -402,7 +402,7 @@ static void output_thread(void *data)
     }
 
     sched_params = (struct flb_sched_timer_coro_cb_params *) FLB_TLS_GET(sched_timer_coro_cb_params);
-    if (sched_params != NULL) {
+    if (sched_params != NULL && sched_params->magic == FLB_SCHED_TLS_MAGIC) {
         flb_free(sched_params);
         FLB_TLS_SET(sched_timer_coro_cb_params, NULL);
     }