diff --git a/storage/innobase/include/os0thread.h b/storage/innobase/include/os0thread.h
index 07f9e14..eab0f67 100644
--- a/storage/innobase/include/os0thread.h
+++ b/storage/innobase/include/os0thread.h
@@ -115,9 +115,23 @@ os_thread_create_func(
 	os_thread_id_t*		thread_id);	/*!< out: id of the created
 						thread, or NULL */
 
-/** Exits the current thread. */
+/**
+Waits until the specified thread completes and joins it. Its return value is
+ignored.
+
+@param	thread	thread to join */
+void
+os_thread_join(
+	os_thread_id_t	thread);
+
+/**
+Exits the current thread.
+
+@param	detach	if true, the thread will be detached right before exiting. If
+false, another thread is responsible for joining this thread */
 void
-os_thread_exit()
+os_thread_exit(
+	bool	detach	= true)
 	UNIV_COLD MY_ATTRIBUTE((noreturn));
 
 /*****************************************************************//**
diff --git a/storage/innobase/include/row0ftsort.h b/storage/innobase/include/row0ftsort.h
index 50d80f5..5713822 100644
--- a/storage/innobase/include/row0ftsort.h
+++ b/storage/innobase/include/row0ftsort.h
@@ -87,6 +87,7 @@ struct fts_psort_t {
 	ulint			state;		/*!< parent thread state */
 	fts_doc_list_t		fts_doc_list;	/*!< doc list to process */
 	fts_psort_common_t*	psort_common;	/*!< ptr to all psort info */
+	os_thread_id_t		thread_hdl;	/*!< thread handle */
 	dberr_t			error;		/*!< db error during psort */
 	ulint			memory_used;	/*!< memory used by fts_doc_list */
 	ib_mutex_t		mutex;		/*!< mutex for fts_doc_list */
diff --git a/storage/innobase/os/os0thread.cc b/storage/innobase/os/os0thread.cc
index d8691b1..9b7f5ea 100644
--- a/storage/innobase/os/os0thread.cc
+++ b/storage/innobase/os/os0thread.cc
@@ -188,9 +188,30 @@ os_thread_create_func(
 	}
 }
 
-/** Exits the current thread. */
+/**
+Waits until the specified thread completes and joins it. Its return value is
+ignored.
+
+@param	thread	thread to join */
+void
+os_thread_join(
+	os_thread_id_t	thread)
+{
+	int ret	MY_ATTRIBUTE((unused)) = pthread_join(thread, NULL);
+
+	/* Waiting on already-quit threads is allowed */
+	ut_ad(ret == 0 || ret == ESRCH);
+}
+
+
+/**
+Exits the current thread.
+
+@param	detach	if true, the thread will be detached right before exiting. If
+false, another thread is responsible for joining this thread */
 void
-os_thread_exit()
+os_thread_exit(
+	bool	detach)
 {
 #ifdef UNIV_DEBUG_THREAD_CREATION
 	ib::info() << "Thread exits, id "
@@ -217,7 +238,8 @@ os_thread_exit()
 	ExitThread(0);
 #else
 	mutex_exit(&thread_mutex);
-	pthread_detach(pthread_self());
+	if (detach)
+		pthread_detach(pthread_self());
 	pthread_exit(NULL);
 #endif
 }
diff --git a/storage/innobase/row/row0ftsort.cc b/storage/innobase/row/row0ftsort.cc
index 7d78f68..cea6a30 100644
--- a/storage/innobase/row/row0ftsort.cc
+++ b/storage/innobase/row/row0ftsort.cc
@@ -1069,7 +1069,7 @@ fts_parallel_merge(
 	os_event_set(psort_info->psort_common->merge_event);
 	psort_info->child_status = FTS_CHILD_EXITING;
 
-	os_thread_exit();
+	os_thread_exit(false);
 
 	OS_THREAD_DUMMY_RETURN;
 }
@@ -1082,7 +1082,6 @@ row_fts_start_parallel_merge(
 	fts_psort_t*	merge_info)	/*!< in: parallel sort info */
 {
 	int		i = 0;
-	os_thread_id_t	thd_id;
 
 	/* Kick off merge/insert threads */
 	for (i = 0; i <  FTS_NUM_AUX_INDEX; i++) {
@@ -1091,7 +1090,7 @@ row_fts_start_parallel_merge(
 
 		os_thread_create(fts_parallel_merge,
 				 (void*) &merge_info[i],
-				 &thd_id);
+				 &merge_info[i].thread_hdl);
 	}
 }
 
diff --git a/storage/innobase/row/row0merge.cc b/storage/innobase/row/row0merge.cc
index 22ab3ea..71b3fd4 100644
--- a/storage/innobase/row/row0merge.cc
+++ b/storage/innobase/row/row0merge.cc
@@ -4486,6 +4486,13 @@ wait_again:
 						" threads exited when creating"
 						" FTS index '"
 						<< indexes[i]->name << "'";
+				} else {
+					for (j = 0; j < FTS_NUM_AUX_INDEX;
+					     j++) {
+
+					    os_thread_join(merge_info[j]
+							   .thread_hdl);
+					}
 				}
 			} else {
 				/* This cannot report duplicates; an