--- ./src/io.c.orig	2020-10-12 17:18:02.000000000 +0200
+++ ./src/io.c	2020-10-18 10:34:54.061491515 +0200
@@ -44,6 +44,7 @@
 #include <math.h>
 #include <unistd.h>
 #include <errno.h>
+#include <stdatomic.h>
 
 #include "calcurse.h"
 #include "sha1.h"
@@ -69,6 +70,8 @@
 static char apts_sha1[SHA1_DIGESTLEN * 2 + 1];
 static char todo_sha1[SHA1_DIGESTLEN * 2 + 1];
 
+static atomic_flag psave_thread_cancel;
+
 /* Ask user for a file name to export data to. */
 static FILE *get_export_stream(enum export_type type)
 {
@@ -1453,13 +1456,16 @@
 /* Thread used to periodically save data. */
 static void *io_psave_thread(void *arg)
 {
+	atomic_flag_clear(&psave_thread_cancel);
+
 	int delay = conf.periodic_save;
 	EXIT_IF(delay < 0, _("Invalid delay"));
 	char *mesg = _("Periodic save cancelled. Data files have changed. "
 		     "Save and merge interactively");
 
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 	for (;;) {
+		if (atomic_flag_test_and_set(&psave_thread_cancel)) pthread_exit(NULL);
+		atomic_flag_clear(&psave_thread_cancel);
 		sleep(delay * MININSEC);
 		pthread_mutex_lock(&io_periodic_save_mutex);
 		if (io_save_cal(periodic) == IO_SAVE_CANCEL)
@@ -1483,8 +1489,7 @@
 
 	/* Lock the mutex to avoid cancelling the thread during saving. */
 	pthread_mutex_lock(&io_periodic_save_mutex);
-	pthread_cancel(io_t_psave);
-	pthread_join(io_t_psave, NULL);
+	atomic_flag_test_and_set(&psave_thread_cancel);
 	pthread_mutex_unlock(&io_periodic_save_mutex);
 	io_t_psave = pthread_self();
 }
diff -uNr calcurse-4.6.0/src/notify.c calcurse-4.6.0.mod/src/notify.c
--- calcurse-4.6.0/src/notify.c	2020-02-04 23:46:34.000000000 +0200
+++ calcurse-4.6.0.mod/src/notify.c	2020-10-01 20:39:57.884475331 +0300
@@ -38,6 +38,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <stdatomic.h>
 
 #include "calcurse.h"
 
@@ -55,6 +56,8 @@
 static struct notify_app notify_app;
 static pthread_attr_t detached_thread_attr;
 
+static atomic_flag main_thread_cancel;
+
 /*
  * Return the number of seconds before next appointment
  * (0 if no upcoming appointment).
@@ -196,8 +199,7 @@
 	if (pthread_equal(notify_t_main, pthread_self()))
 		return;
 
-	pthread_cancel(notify_t_main);
-	pthread_join(notify_t_main, NULL);
+	atomic_flag_test_and_set(&main_thread_cancel);
 	notify_t_main = pthread_self();
 }
 
@@ -334,6 +336,8 @@
 /* ARGSUSED0 */
 static void *notify_main_thread(void *arg)
 {
+	atomic_flag_clear(&main_thread_cancel);
+
 	const unsigned thread_sleep = 1;
 	const unsigned check_app = MININSEC;
 	int elapse = 0;
@@ -346,6 +350,8 @@
 	pthread_cleanup_push(notify_main_thread_cleanup, NULL);
 
 	for (;;) {
+		if (atomic_flag_test_and_set(&main_thread_cancel)) pthread_exit(NULL);
+		atomic_flag_clear(&main_thread_cancel);
 		ntimer = time(NULL);
 		localtime_r(&ntimer, &ntime);
 		pthread_mutex_lock(&notify.mutex);
diff -uNr calcurse-4.6.0/src/ui-calendar.c calcurse-4.6.0.mod/src/ui-calendar.c
--- calcurse-4.6.0/src/ui-calendar.c	2020-02-04 23:46:34.000000000 +0200
+++ calcurse-4.6.0.mod/src/ui-calendar.c	2020-10-01 20:40:09.024576943 +0300
@@ -41,6 +41,7 @@
 #include <time.h>
 #include <math.h>
 #include <langinfo.h>
+#include <stdatomic.h>
 
 #include "calcurse.h"
 
@@ -59,6 +60,8 @@
 static int monthly_view_cache_valid = 0;
 static int monthly_view_cache_month = 0;
 
+static atomic_flag date_thread_cancel;
+
 /* Switch between calendar views (monthly view is selected by default). */
 void ui_calendar_view_next(void)
 {
@@ -89,9 +92,13 @@
 /* ARGSUSED0 */
 static void *ui_calendar_date_thread(void *arg)
 {
+	atomic_flag_clear(&date_thread_cancel);
+
 	time_t actual, tomorrow;
 
 	for (;;) {
+		if (atomic_flag_test_and_set(&date_thread_cancel)) pthread_exit(NULL);
+		atomic_flag_clear(&date_thread_cancel);
 		tomorrow = date2sec(today, 24, 0);
 
 		while ((actual = time(NULL)) < tomorrow)
@@ -118,8 +125,7 @@
 	if (pthread_equal(ui_calendar_t_date, pthread_self()))
 		return;
 
-	pthread_cancel(ui_calendar_t_date);
-	pthread_join(ui_calendar_t_date, NULL);
+	atomic_flag_test_and_set(&date_thread_cancel);
 	ui_calendar_t_date = pthread_self();
 }