diff --git a/src/time/timer_create.c b/src/time/timer_create.c
index 4bef2390..117e5ec6 100644
--- a/src/time/timer_create.c
+++ b/src/time/timer_create.c
@@ -11,9 +11,15 @@ struct ksigevent {
 	int sigev_tid;
 };
 
+struct worker {
+	pid_t tid;
+	volatile int deleted;
+};
+
 struct start_args {
 	pthread_barrier_t b;
 	struct sigevent *sev;
+	struct worker *w;
 };
 
 static void dummy_0()
@@ -38,11 +44,15 @@ static void *start(void *arg)
 	pthread_t self = __pthread_self();
 	struct start_args *args = arg;
 	jmp_buf jb;
+	struct worker w = { self->tid };
 
 	void (*notify)(union sigval) = args->sev->sigev_notify_function;
 	union sigval val = args->sev->sigev_value;
+	args->w = &w;
 
 	pthread_barrier_wait(&args->b);
+	if (self->timer_id < 0)
+		return 0;
 	for (;;) {
 		siginfo_t si;
 		while (sigwaitinfo(SIGTIMER_SET, &si) < 0);
@@ -51,9 +61,9 @@ static void *start(void *arg)
 			notify(val);
 			pthread_cleanup_pop(1);
 		}
-		if (self->timer_id < 0) break;
+		if (w.deleted) break;
 	}
-	__syscall(SYS_timer_delete, self->timer_id & INT_MAX);
+	__syscall(SYS_timer_delete, self->timer_id);
 	return 0;
 }
 
@@ -118,7 +128,7 @@ int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict
 		td->timer_id = timerid;
 		pthread_barrier_wait(&args.b);
 		if (timerid < 0) return -1;
-		*res = (void *)(INTPTR_MIN | (uintptr_t)td>>1);
+		*res = (void *)(INTPTR_MIN | (uintptr_t)args.w>>1);
 		break;
 	default:
 		errno = EINVAL;
diff --git a/src/time/timer_delete.c b/src/time/timer_delete.c
index b0bfac09..80baa920 100644
--- a/src/time/timer_delete.c
+++ b/src/time/timer_delete.c
@@ -5,9 +5,12 @@
 int timer_delete(timer_t t)
 {
 	if ((intptr_t)t < 0) {
-		pthread_t td = (void *)((uintptr_t)t << 1);
-		a_store(&td->timer_id, td->timer_id | INT_MIN);
-		__syscall(SYS_tkill, td->tid, SIGTIMER);
+		struct worker {
+			pid_t tid;
+			volatile int deleted;
+		} *w = (void *)((uintptr_t)t << 1);
+		a_store(&w->deleted, 1);
+		__syscall(SYS_tkill, w->tid, SIGTIMER);
 		return 0;
 	}
 	return __syscall(SYS_timer_delete, t);