diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index ca664ea1..2235b55d 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -150,7 +150,7 @@ if (UNIX)
     check_function_exists(posix_openpt HAVE_POSIX_OPENPT)
   endif (openpty_in_libc OR openpty_in_libutil)
 
-  check_function_exists(ptsname    HAVE_PTSNAME)
+  check_function_exists(ptsname_r  HAVE_PTSNAME_R)
   check_function_exists(tcgetattr  HAVE_TCGETATTR)
   check_function_exists(tcsetattr  HAVE_TCSETATTR)
 endif (UNIX)
diff --git a/config-pty.h.cmake b/config-pty.h.cmake
index 3daf8155..3ee54cf3 100644
--- a/config-pty.h.cmake
+++ b/config-pty.h.cmake
@@ -5,7 +5,7 @@
 #cmakedefine HAVE_POSIX_OPENPT 1
 #cmakedefine HAVE_GRANTPT 1
 #cmakedefine HAVE_OPENPTY 1
-#cmakedefine HAVE_PTSNAME 1
+#cmakedefine HAVE_PTSNAME_R 1
 #cmakedefine HAVE_REVOKE 1
 #cmakedefine HAVE_UNLOCKPT 1
 #cmakedefine HAVE_TCGETATTR
diff --git a/kpty/kgrantpty.c b/kpty/kgrantpty.c
index d015c4fc..f11a4348 100644
--- a/kpty/kgrantpty.c
+++ b/kpty/kgrantpty.c
@@ -69,10 +69,9 @@ int main (int argc, char *argv[])
   gid_t         gid;
   uid_t         uid;
   mode_t        mod;
-  char*         tty;
+  char*         tty = 0;
   int           fd;
-#if !defined(HAVE_PTSNAME) && defined(TIOCGPTN)
-  int           ptyno;
+#if defined(HAVE_PTSNAME_R)
   char          ttyb[32];
 #endif
 
@@ -96,14 +95,14 @@ int main (int argc, char *argv[])
   fd = atoi(argv[2]);
 
   /* get slave pty name from master pty file handle *********/
-#ifdef HAVE_PTSNAME
+#ifdef HAVE_PTSNAME_R
+  ::memset(ttyb, '\0', sizeof(ttyb) * sizeof(char));
+  if (ptsname_r(fd, ttyb, sizeof(ttyb)) == 0) {
+     tty = ttyb;
+  if (!tty)
+#else
   tty = ptsname(fd);
   if (!tty)
-#elif defined(TIOCGPTN)
-  if (!ioctl(fd, TIOCGPTN, &ptyno)) {
-    sprintf(ttyb, "/dev/pts/%d", ptyno);
-    tty = ttyb;
-  } else
 #endif
   {
     /* Check that fd is a valid master pseudo terminal.  */
diff --git a/kpty/kpty.cpp b/kpty/kpty.cpp
index 2a02668d..ae74e864 100644
--- a/kpty/kpty.cpp
+++ b/kpty/kpty.cpp
@@ -190,8 +190,6 @@ bool KPty::open()
 
 #else
 
-#if defined(HAVE_PTSNAME) || defined(TIOCGPTN)
-
 #ifdef HAVE_POSIX_OPENPT
   d->masterFd = ::posix_openpt(O_RDWR|O_NOCTTY);
 #elif defined(PTM_DEVICE)
@@ -201,16 +199,15 @@ bool KPty::open()
 #endif
   if (d->masterFd >= 0)
   {
-#ifdef HAVE_PTSNAME
+#ifdef HAVE_PTSNAME_R
+    char ptsn[32];
+    ::memset(ptsn, '\0', sizeof(ptsn) * sizeof(char));
+    if (ptsname_r(fd, ptsn, sizeof(ptsn)) == 0) {
+        d->ttyName = ptsn;
+#else
     char *ptsn = ptsname(d->masterFd);
     if (ptsn) {
         d->ttyName = ptsn;
-#else
-    int ptyno;
-    if (!ioctl(d->masterFd, TIOCGPTN, &ptyno)) {
-        char buf[32];
-        sprintf(buf, "/dev/pts/%d", ptyno);
-        d->ttyName = buf;
 #endif
 #ifdef HAVE_GRANTPT
         if (!grantpt(d->masterFd))
@@ -222,7 +219,6 @@ bool KPty::open()
     ::close(d->masterFd);
     d->masterFd = -1;
   }
-#endif // HAVE_PTSNAME || TIOCGPTN
 
   // Linux device names, FIXME: Trouble on other systems?
   for (const char* s3 = "pqrstuvwxyzabcde"; *s3; s3++)
@@ -332,10 +328,6 @@ bool KPty::open()
 
 bool KPty::open(int fd)
 {
-#if !defined(HAVE_PTSNAME) && !defined(TIOCGPTN)
-    kWarning(175) << "Unsupported attempt to open pty with fd" << fd;
-    return false;
-#else
     Q_D(KPty);
 
     if (d->masterFd >= 0) {
@@ -345,16 +337,15 @@ bool KPty::open(int fd)
 
     d->ownMaster = false;
 
-# ifdef HAVE_PTSNAME
+# ifdef HAVE_PTSNAME_R
+    char ptsn[32];
+    ::memset(ptsn, '\0', sizeof(ptsn) * sizeof(char));
+    if (ptsname_r(fd, ptsn, sizeof(ptsn)) == 0) {
+        d->ttyName = ptsn;
+# else
     char *ptsn = ptsname(fd);
     if (ptsn) {
         d->ttyName = ptsn;
-# else
-    int ptyno;
-    if (!ioctl(fd, TIOCGPTN, &ptyno)) {
-        char buf[32];
-        sprintf(buf, "/dev/pts/%d", ptyno);
-        d->ttyName = buf;
 # endif
     } else {
         kWarning(175) << "Failed to determine pty slave device for fd" << fd;
@@ -368,7 +359,6 @@ bool KPty::open(int fd)
     }
 
     return true;
-#endif
 }
 
 void KPty::closeSlave()