// on Windows (see #5760).
// FIXME: Re-check after Windows has settled to Qt 5.
// ATM, this doesn't work also with Qt 5.4.1 because of still missing
-// glyphs for \llbracket and \rrbracket.
-#if defined(Q_OS_WIN) || defined(Q_CYGWIN_WIN)
+// glyphs for \llbracket and \rrbracket. These last symbols are also
+// missing when compiling on cygwin using the X11 xcb backend.
+#if defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)
QString symbol(ms.fontcode?
QChar(ms.fontcode) : toqstr(docstring(1, ms.unicode)));
QListWidgetItem * lwi = new QListWidgetItem(symbol);