diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index 2620b7791..15b8ce2c1 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -866,4 +866,7 @@ static inline void __ha_compiler_barrier(void)
 	__asm __volatile("" ::: "memory");
 }
 
+/* Dummy I/O handler used by the sync pipe.*/
+void thread_sync_io_handler(int fd);
+
 #endif /* _COMMON_HATHREADS_H */
diff --git a/src/cli.c b/src/cli.c
index ada45a865..f19b5f18b 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -817,6 +817,7 @@ static int cli_io_handler_show_fd(struct appctx *appctx)
 			     (fdt.iocb == conn_fd_handler)  ? "conn_fd_handler" :
 			     (fdt.iocb == dgram_fd_handler) ? "dgram_fd_handler" :
 			     (fdt.iocb == listener_accept)  ? "listener_accept" :
+			     (fdt.iocb == thread_sync_io_handler) ? "thread_sync_io_handler" :
 			     "unknown",
 			     fdt.thread_mask, fdt.update_mask);
 
diff --git a/src/hathreads.c b/src/hathreads.c
index fd0eb6846..0d0b3761a 100644
--- a/src/hathreads.c
+++ b/src/hathreads.c
@@ -33,7 +33,9 @@ struct lock_stat lock_stats[LOCK_LABELS];
 #endif
 
 /* Dummy I/O handler used by the sync pipe.*/
-static void thread_sync_io_handler(int fd) { }
+void thread_sync_io_handler(int fd)
+{
+}
 
 /* Initializes the sync point. It creates a pipe used by threads to wakup all
  * others when a sync is requested. It also initialize the mask of all create