diff --git a/src/gallium/state_trackers/xorg/xorg_composite.c b/src/gallium/state_trackers/xorg/xorg_composite.c
index 93a3e1b8cf0..733bd53fca8 100644
--- a/src/gallium/state_trackers/xorg/xorg_composite.c
+++ b/src/gallium/state_trackers/xorg/xorg_composite.c
@@ -237,7 +237,7 @@ picture_format_fixups(struct exa_pixmap_priv *pSrc, PicturePtr pSrcPicture, bool
 
    if (pSrc->picture_format == pSrcPicture->format) {
       if (pSrc->picture_format == PICT_a8)
-         return mask ? FS_MASK_LUMINANCE : FS_MASK_LUMINANCE;
+         return mask ? FS_MASK_LUMINANCE : FS_SRC_LUMINANCE;
       return 0;
    }