NSTextAttachment image not showing when drawing using CoreText

For some reason I'm unable to get NSTextAttachment images to draw when using core text, although the same image would display fine when the NSAttributedString is added to an UILabel.

On iOS this rendering will give empty spaces for the NSTextAttachments, for OS X, a placeholder [OBJECT] square image is rendered for each NSTextAttachment instead. Is there something else that needs to be done in order to render images with CoreText?

The rendering code:

CGFloat contextHeight = CGBitmapContextGetHeight(context);
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)_attributedString);
CGPathRef path = CGPathCreateWithRect(CGRectMake(rect.origin.x,
                                                 contextHeight - rect.origin.y - rect.size.height,
                                                 rect.size.width,
                                                 rect.size.height), NULL);
CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);
CFRelease(framesetter);
CGPathRelease(path);
CGContextSaveGState(context);
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0.0f, contextHeight);
CGContextScaleCTM(context, 1.0f, -1.0f);
CTFrameDraw(frame, context);
CGContextRestoreGState(context);
CFRelease(frame);