diff --git a/src/r_bsp.cpp b/src/r_bsp.cpp
index 4174ab629..5605272e7 100644
--- a/src/r_bsp.cpp
+++ b/src/r_bsp.cpp
@@ -589,7 +589,7 @@ void R_AddLine (seg_t *line)
 	rw_havehigh = rw_havelow = false;
 
 	// Single sided line?
-	if (backsector == NULL)
+	if (backsector == NULL || (line->linedef->portal && line->sidedef == line->linedef->sidedef[0]))
 	{
 		solid = true;
 	}
@@ -654,9 +654,7 @@ void R_AddLine (seg_t *line)
 		// Window.
 			solid = false;
 		}
-		else if (line->linedef->portal // [ZZ] portals are always drawn, even if there's exactly same sector on both sides
-			
-			|| backsector->lightlevel != frontsector->lightlevel
+		else if (backsector->lightlevel != frontsector->lightlevel
 			|| backsector->GetTexture(sector_t::floor) != frontsector->GetTexture(sector_t::floor)
 			|| backsector->GetTexture(sector_t::ceiling) != frontsector->GetTexture(sector_t::ceiling)
 			|| curline->sidedef->GetTexture(side_t::mid).isValid()
diff --git a/src/r_main.cpp b/src/r_main.cpp
index 676b59ac3..ef942734e 100644
--- a/src/r_main.cpp
+++ b/src/r_main.cpp
@@ -639,7 +639,7 @@ void R_HighlightPortal (PortalDrawseg* pds)
 
 		if (x == pds->x1 || x == pds->x2)
 		{
-			RenderTarget->DrawLine(x, Ytop, x, Ybottom, color, 0);
+			RenderTarget->DrawLine(x, Ytop, x, Ybottom+1, color, 0);
 			continue;
 		}
 
diff --git a/src/r_things.cpp b/src/r_things.cpp
index 03539eeb6..2aa97f7f0 100644
--- a/src/r_things.cpp
+++ b/src/r_things.cpp
@@ -2157,7 +2157,8 @@ void R_DrawSprite (vissprite_t *spr)
 						ds->curline->v1->x - spr->gx, ds->curline->v2->y - ds->curline->v1->y) <= 0))
 		{
 			// seg is behind sprite, so draw the mid texture if it has one
-			if (ds->maskedtexturecol != -1 || ds->bFogBoundary)
+			if (ds->CurrentPortalUniq == CurrentPortalUniq && // [ZZ] instead, portal uniq check is made here
+				(ds->maskedtexturecol != -1 || ds->bFogBoundary))
 				R_RenderMaskedSegRange (ds, r1, r2);
 			continue;
 		}
@@ -2522,9 +2523,6 @@ static void R_DrawMaskedSegsBehindParticle (const vissprite_t *vis)
 	for (unsigned int p = InterestingDrawsegs.Size(); p-- > FirstInterestingDrawseg; )
 	{
 		drawseg_t *ds = &drawsegs[InterestingDrawsegs[p]];
-		// [ZZ] only draw stuff that's inside the same portal as the particle, other portals will care for themselves
-		if (ds->CurrentPortalUniq != vis->CurrentPortalUniq)
-			continue;
 		// kg3D - no fake segs
 		if (ds->fake) continue;
 		if (ds->x1 >= x2 || ds->x2 < x1)
@@ -2533,7 +2531,9 @@ static void R_DrawMaskedSegsBehindParticle (const vissprite_t *vis)
 		}
 		if (Scale (ds->siz2 - ds->siz1, (x2 + x1)/2 - ds->sx1, ds->sx2 - ds->sx1) + ds->siz1 < vis->idepth)
 		{
-			R_RenderMaskedSegRange (ds, MAX<int> (ds->x1, x1), MIN<int> (ds->x2, x2-1));
+			// [ZZ] only draw stuff that's inside the same portal as the particle, other portals will care for themselves
+			if (ds->CurrentPortalUniq == vis->CurrentPortalUniq)
+				R_RenderMaskedSegRange (ds, MAX<int> (ds->x1, x1), MIN<int> (ds->x2, x2-1));
 		}
 	}
 }