diff --git a/src/m_cheat.c b/src/m_cheat.c
index 89334596..3bbaadc5 100644
--- a/src/m_cheat.c
+++ b/src/m_cheat.c
@@ -452,7 +452,7 @@ void Command_RTeleport_f(void)
 	else
 		inty = 0;
 
-	ss = R_PointInSubsector(p->mo->x + intx*FRACUNIT, p->mo->y + inty*FRACUNIT);
+	ss = R_IsPointInSubsector(p->mo->x + intx*FRACUNIT, p->mo->y + inty*FRACUNIT);
 	if (!ss || ss->sector->ceilingheight - ss->sector->floorheight < p->mo->height)
 	{
 		CONS_Alert(CONS_NOTICE, M_GetText("Not a valid location.\n"));
diff --git a/src/p_user.c b/src/p_user.c
index 3867137a..f8dc942c 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -2280,14 +2280,13 @@ static void P_DoClimbing(player_t *player)
 	fixed_t platy;
 	subsector_t *glidesector;
 	boolean climb = true;
-	boolean onesided = ((player->lastsidehit != -1 && player->lastlinehit != -1) && !(lines[player->lastlinehit].backsector));
 
 	platx = P_ReturnThrustX(player->mo, player->mo->angle, player->mo->radius + FixedMul(8*FRACUNIT, player->mo->scale));
 	platy = P_ReturnThrustY(player->mo, player->mo->angle, player->mo->radius + FixedMul(8*FRACUNIT, player->mo->scale));
 
-	glidesector = R_PointInSubsector(player->mo->x + platx, player->mo->y + platy);
+	glidesector = R_IsPointInSubsector(player->mo->x + platx, player->mo->y + platy);
 
-	if (onesided || glidesector->sector != player->mo->subsector->sector)
+	if (!glidesector || glidesector->sector != player->mo->subsector->sector)
 	{
 		boolean floorclimb = false;
 		boolean thrust = false;
@@ -2295,7 +2294,7 @@ static void P_DoClimbing(player_t *player)
 		boolean skyclimber = false;
 		fixed_t floorheight, ceilingheight; // ESLOPE
 
-		if (onesided)
+		if (!glidesector)
 			floorclimb = true;
 		else
 		{
diff --git a/src/r_main.c b/src/r_main.c
index 498f4dab..1b4322b4 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -771,7 +771,7 @@ subsector_t *R_PointInSubsector(fixed_t x, fixed_t y)
 }
 
 //
-// R_IsPointInSubsector, same as above but returns 0 if not in subsector - this does not work in opengl because of polyvertex_t
+// R_IsPointInSubsector, same as above but returns 0 if not in subsector
 //
 subsector_t *R_IsPointInSubsector(fixed_t x, fixed_t y)
 {
@@ -795,7 +795,8 @@ subsector_t *R_IsPointInSubsector(fixed_t x, fixed_t y)
 
 	ret = &subsectors[nodenum & ~NF_SUBSECTOR];
 	for (i = 0; i < ret->numlines; i++)
-		if (R_PointOnSegSide(x, y, &segs[ret->firstline + i]))
+		//if (R_PointOnSegSide(x, y, &segs[ret->firstline + i])) -- breaks in ogl because polyvertex_t cast over vertex pointers
+		if (P_PointOnLineSide(x, y, segs[ret->firstline + i].linedef) != segs[ret->firstline + i].side)
 			return 0;
 
 	return ret;