diff --git a/src/r_plane.c b/src/r_plane.c
index 7439886d7..0f11bcb02 100644
--- a/src/r_plane.c
+++ b/src/r_plane.c
@@ -1014,9 +1014,9 @@ void R_DrawSinglePlane(visplane_t *pl)
 				else if (pl->ffloor->alpha < 243)
 					ds_transmap = transtables + ((tr_trans10-1)<<FF_TRANSSHIFT);
 				else if (pl->ffloor->alpha == FFLOOR_ALPHA_SPECIAL_ADDITIVE)
-					dc_transmap = transtables + ((tr_transadd-1)<<FF_TRANSSHIFT);
+					ds_transmap = transtables + ((tr_transadd-1)<<FF_TRANSSHIFT);
 				else if (pl->ffloor->alpha == FFLOOR_ALPHA_SPECIAL_SUBTRACTIVE)
-					dc_transmap = transtables + ((tr_transsub-1)<<FF_TRANSSHIFT);
+					ds_transmap = transtables + ((tr_transsub-1)<<FF_TRANSSHIFT);
 				else // Opaque, but allow transparent flat pixels
 					spanfunctype = SPANDRAWFUNC_SPLAT;