diff --git a/include/fluent-bit/flb_output.h b/include/fluent-bit/flb_output.h
index 5be4ec6d72c..ce9f1a0c015 100644
--- a/include/fluent-bit/flb_output.h
+++ b/include/fluent-bit/flb_output.h
@@ -76,44 +76,6 @@
 
 struct flb_output_flush;
 
-struct flb_out_thread_instance {
-    struct mk_event event;               /* event context to associate events */
-    struct mk_event_loop *evl;           /* thread event loop context */
-    struct flb_bucket_queue *evl_bktq;    /* bucket queue for evl track event priority */
-    flb_pipefd_t ch_parent_events[2];    /* channel to receive parent notifications */
-    flb_pipefd_t ch_thread_events[2];    /* channel to send messages local event loop */
-    struct flb_output_instance *ins;     /* output plugin instance */
-    struct flb_config *config;
-    struct flb_tp_thread *th;
-    struct mk_list _head;
-
-    /*
-     * In multithread mode, we move some contexts to independent references per thread
-     * so we can avoid to have shared resources and mutexes.
-     *
-     * The following 'coro' fields maintains a state of co-routines inside the thread
-     * event loop.
-     *
-     * note: in single-thread mode, the same fields are in 'struct flb_output_instance'.
-     */
-    int flush_id;                             /* coroutine id counter */
-    struct mk_list flush_list;                /* flush context list */
-    struct mk_list flush_list_destroy;        /* flust context destroy list */
-
-    /*
-     * If the main engine (parent thread) needs to query the number of active
-     * 'flushes' running by a threaded instance, then the access to the 'flush_list'
-     * must be protected: we use 'flush_mutex for that purpose.
-     */
-    pthread_mutex_t flush_mutex;         /* mutex for 'flush_list' */
-
-    /* List of mapped 'upstream' contexts */
-    struct mk_list upstreams;
-
-    /* Each event loop has a scheduler instance */
-    struct flb_sched *sched;
-};
-
 struct flb_out_thread_instance;
 int flb_output_thread_pool_coros_size(struct flb_output_instance *ins);
 struct flb_out_thread_instance *flb_output_thread_instance_get();