diff --git a/libs/main/thread/pithread.cpp b/libs/main/thread/pithread.cpp
index 0c6d8913..fef59b51 100644
--- a/libs/main/thread/pithread.cpp
+++ b/libs/main/thread/pithread.cpp
@@ -770,11 +770,14 @@ bool PIThread::_startThread(void * func) {
 	if (ret == 0) {
 		PIString tname = name().simplified();
 		tname.elide(15, 0.4f).resize(15, PIChar('\0'));
+		PIByteArray tn_data = tname.toAscii();
+		tn_data.resize(16);
+		tn_data.back() = 0;
 #  ifdef MAC_OS
-		pthread_setname_np(tname.dataAscii());
+		pthread_setname_np(tn_data.data());
 		pthread_threadid_np(PRIVATE->thread, (__uint64_t *)&tid_);
 #  else
-		pthread_setname_np(PRIVATE->thread, tname.dataAscii());
+		pthread_setname_np(PRIVATE->thread, tn_data.data());
 #  endif
 		setPriority(priority_);
 		return true;