Qt5.4 ignoring fontconfig 'antialias' setting

In Qt5.3.1, my application honors the antialias settings in my fonts.conf file. See Qt5.3.1_antialias=false.png and Qt5.3.1_antialias=true.png.

These correspond to the follow settings in the fonts.conf file for the specific font being used:

<edit mode="assign" name="antialias">
 <bool>false</bool>
</edit>

<edit mode="assign" name="antialias">
 <bool>true</bool>
</edit>

However, in Qt5.4, it appears to be ignoring the setting. See Qt5.4_antialias=false.png and Qt5.4_antialias=true.png. In this case, it always performs antialiasing (according to what I specify via gnome-tweak-tool) even when antialiasing is disabled for the font in fonts.conf.

In all cases I'm using the Linux 64-bit offline installs for Qt.