diff --git a/qt4/src/poppler-qiodeviceoutstream.cc b/qt4/src/poppler-qiodeviceoutstream.cc
index 11fab97..4716952 100644
--- a/qt4/src/poppler-qiodeviceoutstream.cc
+++ b/qt4/src/poppler-qiodeviceoutstream.cc
@@ -58,14 +58,11 @@ void QIODeviceOutStream::printf(const char *format, ...)
 {
   va_list ap;
   va_start(ap, format);
-  char* buf = 0;
-  size_t bufsize = 0;
-  FILE* stream = open_memstream(&buf, &bufsize);
-  vfprintf(stream, format, ap);
+  QString s;
+  s.vsprintf(format, ap);
   va_end(ap);
-  fclose(stream);
-  m_device->write(buf, bufsize);
-  free(buf);
+  QByteArray ba = s.toAscii();
+  m_device->write(ba.constData(), ba.size());
 }
 
 }