diff --git a/src/deh_tables.c b/src/deh_tables.c
index 3580e15c6..05f61f6e5 100644
--- a/src/deh_tables.c
+++ b/src/deh_tables.c
@@ -4283,8 +4283,9 @@ const char *const MOBJTYPE_LIST[] = {  // array length left dynamic for sanity t
 	"MT_POLYANCHOR",
 	"MT_POLYSPAWN",
 
-	// Skybox objects
+	// Portal objects
 	"MT_SKYBOX",
+	"MT_PORTALREFPOINT",
 
 	// Debris
 	"MT_SPARK", //spark
diff --git a/src/info.c b/src/info.c
index 11e9c9fe8..f71a2bd1c 100644
--- a/src/info.c
+++ b/src/info.c
@@ -20759,6 +20759,33 @@ mobjinfo_t mobjinfo[NUMMOBJTYPES] =
 		S_NULL          // raisestate
 	},
 
+	{           // MT_PORTALREFPOINT
+		781,            // doomednum
+		S_INVISIBLE,    // spawnstate
+		1000,           // spawnhealth
+		S_NULL,         // seestate
+		sfx_None,       // seesound
+		8,              // reactiontime
+		sfx_None,       // attacksound
+		S_NULL,         // painstate
+		0,              // painchance
+		sfx_None,       // painsound
+		S_NULL,         // meleestate
+		S_NULL,         // missilestate
+		S_NULL,         // deathstate
+		S_NULL,         // xdeathstate
+		sfx_None,       // deathsound
+		0,              // speed
+		12*FRACUNIT,    // radius
+		24*FRACUNIT,    // height
+		0,              // display offset
+		10,             // mass
+		0,              // damage
+		sfx_None,       // activesound
+		MF_SCENERY|MF_NOBLOCKMAP|MF_NOGRAVITY, // flags
+		S_NULL          // raisestate
+	},
+
 	{           // MT_SPARK
 		-1,             // doomednum
 		S_SPRK1,        // spawnstate
diff --git a/src/info.h b/src/info.h
index 5c7a9f3fd..00822faea 100644
--- a/src/info.h
+++ b/src/info.h
@@ -5114,8 +5114,9 @@ typedef enum mobj_type
 	MT_POLYANCHOR,
 	MT_POLYSPAWN,
 
-	// Skybox objects
+	// Portal objects
 	MT_SKYBOX,
+	MT_PORTALREFPOINT,
 
 	// Debris
 	MT_SPARK, //spark
diff --git a/src/p_mobj.c b/src/p_mobj.c
index de2c3a72c..f7ad7616d 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -12822,6 +12822,28 @@ static boolean P_SetupSpawnedMapThing(mapthing_t *mthing, mobj_t *mobj, boolean
 			skyboxviewpnts[tag] = mobj;
 		break;
 	}
+	case MT_PORTALREFPOINT:
+		{
+			size_t i;
+			for (i = 0; i < numsectors; i++)
+			{
+				sector_t *targetsec = &sectors[i];
+				for (int j = 0; j < targetsec->tags.count; j++)
+				{
+					if ((mthing->extrainfo == targetsec->tags.tags[j]) && (GETSECSPECIAL(targetsec->special, 3) == 1))
+					{
+						// origin
+						if (targetsec == mobj->subsector->sector)
+							targetsec->portals[1] = mobj;
+							// target
+							else
+							targetsec->portals[0] = mobj;
+							break;
+					}
+				}
+			}
+		}
+		break;
 	case MT_EGGSTATUE:
 		if (mthing->args[1])
 		{
diff --git a/src/p_setup.c b/src/p_setup.c
index e289b8346..51c14e147 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -989,6 +989,8 @@ static void P_InitializeSector(sector_t *ss)
 	ss->floordata = NULL;
 	ss->ceilingdata = NULL;
 	ss->lightingdata = NULL;
+	ss->portals[0] = NULL;
+	ss->portals[1] = NULL;
 	ss->fadecolormapdata = NULL;
 
 	ss->heightsec = -1;
diff --git a/src/r_bsp.c b/src/r_bsp.c
index 42e050adf..70a9dbd94 100644
--- a/src/r_bsp.c
+++ b/src/r_bsp.c
@@ -908,7 +908,7 @@ static void R_Subsector(size_t num)
 		|| frontsector->floorpic == skyflatnum
 		|| (frontsector->heightsec != -1 && sectors[frontsector->heightsec].ceilingpic == skyflatnum))
 	{
-		floorplane = R_FindPlane(frontsector->floorheight, frontsector->floorpic, floorlightlevel,
+		floorplane = R_FindPlane(frontsector, frontsector->floorheight, frontsector->floorpic, floorlightlevel,
 			frontsector->floorxoffset, frontsector->flooryoffset, frontsector->floorangle, floorcolormap, NULL, NULL, frontsector->f_slope);
 	}
 	else
@@ -918,7 +918,7 @@ static void R_Subsector(size_t num)
 		|| frontsector->ceilingpic == skyflatnum
 		|| (frontsector->heightsec != -1 && sectors[frontsector->heightsec].floorpic == skyflatnum))
 	{
-		ceilingplane = R_FindPlane(frontsector->ceilingheight, frontsector->ceilingpic,
+		ceilingplane = R_FindPlane(frontsector, frontsector->ceilingheight, frontsector->ceilingpic,
 			ceilinglightlevel, frontsector->ceilingxoffset, frontsector->ceilingyoffset, frontsector->ceilingangle,
 			ceilingcolormap, NULL, NULL, frontsector->c_slope);
 	}
@@ -961,7 +961,7 @@ static void R_Subsector(size_t num)
 				light = R_GetPlaneLight(frontsector, planecenterz,
 					viewz < heightcheck);
 
-				ffloor[numffloors].plane = R_FindPlane(*rover->bottomheight, *rover->bottompic,
+				ffloor[numffloors].plane = R_FindPlane(rover->master->frontsector, *rover->bottomheight, *rover->bottompic,
 					*frontsector->lightlist[light].lightlevel, *rover->bottomxoffs,
 					*rover->bottomyoffs, *rover->bottomangle, *frontsector->lightlist[light].extra_colormap, rover, NULL, *rover->b_slope);
 
@@ -990,7 +990,7 @@ static void R_Subsector(size_t num)
 			{
 				light = R_GetPlaneLight(frontsector, planecenterz, viewz < heightcheck);
 
-				ffloor[numffloors].plane = R_FindPlane(*rover->topheight, *rover->toppic,
+				ffloor[numffloors].plane = R_FindPlane(rover->master->frontsector, *rover->topheight, *rover->toppic,
 					*frontsector->lightlist[light].lightlevel, *rover->topxoffs, *rover->topyoffs, *rover->topangle,
 					*frontsector->lightlist[light].extra_colormap, rover, NULL, *rover->t_slope);
 
@@ -1032,7 +1032,7 @@ static void R_Subsector(size_t num)
 				&& (viewz < polysec->floorheight))
 			{
 				light = R_GetPlaneLight(frontsector, polysec->floorheight, viewz < polysec->floorheight);
-				ffloor[numffloors].plane = R_FindPlane(polysec->floorheight, polysec->floorpic,
+				ffloor[numffloors].plane = R_FindPlane(polysec, polysec->floorheight, polysec->floorpic,
 					(light == -1 ? frontsector->lightlevel : *frontsector->lightlist[light].lightlevel), polysec->floorxoffset, polysec->flooryoffset,
 					polysec->floorangle-po->angle,
 					(light == -1 ? frontsector->extra_colormap : *frontsector->lightlist[light].extra_colormap), NULL, po,
@@ -1056,7 +1056,7 @@ static void R_Subsector(size_t num)
 				&& (viewz > polysec->ceilingheight))
 			{
 				light = R_GetPlaneLight(frontsector, polysec->floorheight, viewz < polysec->floorheight);
-				ffloor[numffloors].plane = R_FindPlane(polysec->ceilingheight, polysec->ceilingpic,
+				ffloor[numffloors].plane = R_FindPlane(polysec, polysec->ceilingheight, polysec->ceilingpic,
 					(light == -1 ? frontsector->lightlevel : *frontsector->lightlist[light].lightlevel), polysec->ceilingxoffset, polysec->ceilingyoffset, polysec->ceilingangle-po->angle,
 					(light == -1 ? frontsector->extra_colormap : *frontsector->lightlist[light].extra_colormap), NULL, po,
 					NULL); // will ffloors be slopable eventually?
diff --git a/src/r_defs.h b/src/r_defs.h
index dfd2d6d70..61f9eaa4e 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -494,6 +494,9 @@ typedef struct sector_s
 
 	// colormap structure
 	extracolormap_t *spawn_extra_colormap;
+
+	// floor portals
+	mobj_t *portals[2];
 } sector_t;
 
 //
diff --git a/src/r_main.c b/src/r_main.c
index 952171405..8a0575d66 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -1513,10 +1513,8 @@ void R_RenderPlayerView(player_t *player)
 	R_ClipSprites(drawsegs, NULL);
 	PS_STOP_TIMING(ps_sw_spritecliptime);
 
-
 	// Add skybox portals caused by sky visplanes.
-	if (cv_skybox.value && skyboxmo[0])
-		Portal_AddSkyboxPortals();
+	Portal_AddSkyboxPortals();
 
 	// Portal rendering. Hijacks the BSP traversal.
 	PS_START_TIMING(ps_sw_portaltime);
diff --git a/src/r_plane.c b/src/r_plane.c
index 29ce26b29..a24ea9d28 100644
--- a/src/r_plane.c
+++ b/src/r_plane.c
@@ -390,7 +390,7 @@ static visplane_t *new_visplane(unsigned hash)
 //              Same height, same flattexture, same lightlevel.
 //              If not, allocates another of them.
 //
-visplane_t *R_FindPlane(fixed_t height, INT32 picnum, INT32 lightlevel,
+visplane_t *R_FindPlane(sector_t *sector, fixed_t height, INT32 picnum, INT32 lightlevel,
 	fixed_t xoff, fixed_t yoff, angle_t plangle, extracolormap_t *planecolormap,
 	ffloor_t *pfloor, polyobj_t *polyobj, pslope_t *slope)
 {
@@ -447,6 +447,7 @@ visplane_t *R_FindPlane(fixed_t height, INT32 picnum, INT32 lightlevel,
 				&& lightlevel == check->lightlevel
 				&& xoff == check->xoffs && yoff == check->yoffs
 				&& planecolormap == check->extra_colormap
+				&& !pfloor && !check->ffloor
 				&& check->viewx == viewx && check->viewy == viewy && check->viewz == viewz
 				&& check->viewangle == viewangle
 				&& check->plangle == plangle
@@ -477,6 +478,7 @@ visplane_t *R_FindPlane(fixed_t height, INT32 picnum, INT32 lightlevel,
 	check->viewz = viewz;
 	check->viewangle = viewangle;
 	check->plangle = plangle;
+	check->sector = sector;
 	check->polyobj = polyobj;
 	check->slope = slope;
 
@@ -553,6 +555,7 @@ visplane_t *R_CheckPlane(visplane_t *pl, INT32 start, INT32 stop)
 		new_pl->viewz = pl->viewz;
 		new_pl->viewangle = pl->viewangle;
 		new_pl->plangle = pl->plangle;
+		new_pl->sector = pl->sector;
 		new_pl->polyobj = pl->polyobj;
 		new_pl->slope = pl->slope;
 		pl = new_pl;
diff --git a/src/r_plane.h b/src/r_plane.h
index 917e8b041..a3ae84f65 100644
--- a/src/r_plane.h
+++ b/src/r_plane.h
@@ -50,6 +50,7 @@ typedef struct visplane_s
 
 	fixed_t xoffs, yoffs; // Scrolling flats.
 
+	sector_t *sector;
 	struct ffloor_s *ffloor;
 	polyobj_t *polyobj;
 	pslope_t *slope;
@@ -75,7 +76,7 @@ void R_ClearPlanes(void);
 void R_ClearFFloorClips (void);
 
 void R_DrawPlanes(void);
-visplane_t *R_FindPlane(fixed_t height, INT32 picnum, INT32 lightlevel, fixed_t xoff, fixed_t yoff, angle_t plangle,
+visplane_t *R_FindPlane(sector_t *sector, fixed_t height, INT32 picnum, INT32 lightlevel, fixed_t xoff, fixed_t yoff, angle_t plangle,
 	extracolormap_t *planecolormap, ffloor_t *ffloor, polyobj_t *polyobj, pslope_t *slope);
 visplane_t *R_CheckPlane(visplane_t *pl, INT32 start, INT32 stop);
 void R_ExpandPlane(visplane_t *pl, INT32 start, INT32 stop);
diff --git a/src/r_portal.c b/src/r_portal.c
index e594f960a..1a2b905f9 100644
--- a/src/r_portal.c
+++ b/src/r_portal.c
@@ -16,11 +16,13 @@
 #include "r_main.h"
 #include "doomstat.h"
 #include "p_spec.h" // Skybox viewpoints
+#include "p_local.h"
 #include "z_zone.h"
 #include "r_things.h"
 #include "r_sky.h"
 
 UINT8 portalrender;			/**< When rendering a portal, it establishes the depth of the current BSP traversal. */
+UINT8 floorportalrender;	/**< Same deal, but for floorportals. */
 
 // Linked list for portals.
 portal_t *portal_base, *portal_cap;
@@ -34,6 +36,7 @@ boolean portalline; // is curline a portal seg?
 void Portal_InitList (void)
 {
 	portalrender = 0;
+	floorportalrender = 0;
 	portal_base = portal_cap = NULL;
 }
 
@@ -306,6 +309,45 @@ void Portal_AddSkybox (const visplane_t* plane)
 	portal->clipline = -1;
 }
 
+/** Creates a floor portal out of a visplane.
+ *
+ * Mostly the same as Portal_AddSkybox.
+ */
+void Portal_AddFloorPortal (const visplane_t* plane)
+{
+	INT16 start, end;
+	portal_t* portal;
+	sector_t *portalsector = plane->sector;
+	mobj_t *portalmobj = portalsector->portals[0];
+	mobj_t *refmobj = portalsector->portals[1];
+	fixed_t refx, refy;
+
+	if (TrimVisplaneBounds(plane, &start, &end))
+		return;
+
+	portal = Portal_Add(start, end);
+
+	Portal_ClipVisplane(plane, portal);
+
+	if ((refmobj != NULL) && !(P_MobjWasRemoved(refmobj)))
+	{
+		refx = (refmobj->x - viewx);
+		refy = (refmobj->y - viewy);
+	}
+	else
+	{
+		refx = (portalsector->soundorg.x - viewx);
+		refy = (portalsector->soundorg.y - viewy);
+	}
+
+	portal->viewx = portalmobj->x - refx;
+	portal->viewy = portalmobj->y - refy;
+	portal->viewz = portalmobj->z + viewz;
+	portal->viewangle = viewangle + portalmobj->angle;
+
+	portal->clipline = -1;
+}
+
 /** Creates portals for the currently existing sky visplanes.
  * The visplanes are also removed and cleared from the list.
  */
@@ -319,13 +361,35 @@ void Portal_AddSkyboxPortals (void)
 	{
 		for (pl = visplanes[i]; pl; pl = pl->next)
 		{
+			// true if added a portal for this visplane
+			boolean addedportal = false;
+			boolean floorportalpresent = (pl->sector->portals[0] != NULL && !P_MobjWasRemoved(pl->sector->portals[0]));
+
+			// skybox portal
 			if (pl->picnum == skyflatnum)
 			{
-				Portal_AddSkybox(pl);
+				if (cv_skybox.value && skyboxmo[0])
+				{
+					Portal_AddSkybox(pl);
+					addedportal = true;
+				}
+			}
+			// floor portal
+			else if (floorportalpresent)
+			{
+				if (floorportalrender < cv_maxportals.value)
+				{
+					Portal_AddFloorPortal(pl);
+					floorportalrender++;
+					addedportal = true;
+				}
+			}
 
+			// don't render this visplane anymore
+			if (addedportal)
+			{
 				pl->minx = 0;
 				pl->maxx = -1;
-
 				count++;
 			}
 		}
diff --git a/src/r_portal.h b/src/r_portal.h
index f90f05fbc..14b49f289 100644
--- a/src/r_portal.h
+++ b/src/r_portal.h
@@ -44,15 +44,17 @@ typedef struct portal_s
 extern portal_t* portal_base;
 extern portal_t* portal_cap;
 extern UINT8 portalrender;
+extern UINT8 floorportalrender;
 
 extern line_t *portalclipline;
 extern sector_t *portalcullsector;
 extern INT32 portalclipstart, portalclipend;
 
-void Portal_InitList	(void);
-void Portal_Remove		(portal_t* portal);
-void Portal_Add2Lines	(const INT32 line1, const INT32 line2, const INT32 x1, const INT32 x2);
-void Portal_AddSkybox	(const visplane_t* plane);
+void Portal_InitList		(void);
+void Portal_Remove			(portal_t* portal);
+void Portal_Add2Lines		(const INT32 line1, const INT32 line2, const INT32 x1, const INT32 x2);
+void Portal_AddSkybox		(const visplane_t* plane);
+void Portal_AddFloorPortal	(const visplane_t* plane);
 
 void Portal_ClipRange (portal_t* portal);
 void Portal_ClipApply (const portal_t* portal);