diff --git a/src/p_map.c b/src/p_map.c
index 5cd60127..612f1522 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -1146,13 +1146,17 @@ static boolean PIT_CheckLine(line_t *ld)
 	{
 		tmceilingz = opentop;
 		ceilingline = ld;
+#ifdef ESLOPE
 		tmceilingslope = opentopslope;
+#endif
 	}
 
 	if (openbottom > tmfloorz)
 	{
 		tmfloorz = openbottom;
+#ifdef ESLOPE
 		tmfloorslope = openbottomslope;
+#endif
 	}
 
 	if (highceiling > tmdrpoffceilz)
diff --git a/src/p_maputl.c b/src/p_maputl.c
index 82d9bbfe..6bd94362 100644
--- a/src/p_maputl.c
+++ b/src/p_maputl.c
@@ -527,13 +527,17 @@ void P_LineOpening(line_t *linedef)
 		{
 			opentop = frontheight;
 			highceiling = backheight;
+#ifdef ESLOPE
 			opentopslope = front->c_slope;
+#endif
 		}
 		else
 		{
 			opentop = backheight;
 			highceiling = frontheight;
+#ifdef ESLOPE
 			opentopslope = back->c_slope;
+#endif
 		}
 
 		frontheight = P_GetFloorZ(tmthing, front, tmx, tmy, linedef);
@@ -543,13 +547,17 @@ void P_LineOpening(line_t *linedef)
 		{
 			openbottom = frontheight;
 			lowfloor = backheight;
+#ifdef ESLOPE
 			openbottomslope = front->f_slope;
+#endif
 		}
 		else
 		{
 			openbottom = backheight;
 			lowfloor = frontheight;
+#ifdef ESLOPE
 			openbottomslope = back->f_slope;
+#endif
 		}
 	}
 
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 2bab28bc..9a33eb65 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -752,6 +752,7 @@ boolean P_InsideANonSolidFFloor(mobj_t *mobj, ffloor_t *rover)
 	return true;
 }
 
+#ifdef ESLOPE
 // P_GetFloorZ (and its ceiling counterpart)
 // Gets the floor height (or ceiling height) of the mobj's contact point in sector, assuming object's center if moved to [x, y]
 // If line is supplied, it's a divider line on the sector. Set it to NULL if you're not checking for collision with a line
@@ -855,10 +856,13 @@ static fixed_t HighestOnLine(fixed_t radius, fixed_t x, fixed_t y, line_t *line,
 			P_GetZAt(slope, v2.x, v2.y)
 		);
 }
+#endif
 
 fixed_t P_MobjFloorZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect)
 {
+#ifdef ESLOPE
 	I_Assert(mobj != NULL);
+#endif
 	I_Assert(sector != NULL);
 #ifdef ESLOPE
 	if (sector->f_slope) {
@@ -930,13 +934,23 @@ fixed_t P_MobjFloorZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t
 
 		return HighestOnLine(mobj->radius, x, y, line, slope, lowest);
 	} else // Well, that makes it easy. Just get the floor height
+#else
+	(void)mobj;
+	(void)boundsec;
+	(void)x;
+	(void)y;
+	(void)line;
+	(void)lowest;
+	(void)perfect;
 #endif
 		return sector->floorheight;
 }
 
 fixed_t P_MobjCeilingZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect)
 {
+#ifdef ESLOPE
 	I_Assert(mobj != NULL);
+#endif
 	I_Assert(sector != NULL);
 #ifdef ESLOPE
 	if (sector->c_slope) {
@@ -1008,6 +1022,14 @@ fixed_t P_MobjCeilingZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed
 
 		return HighestOnLine(mobj->radius, x, y, line, slope, lowest);
 	} else // Well, that makes it easy. Just get the ceiling height
+#else
+	(void)mobj;
+	(void)boundsec;
+	(void)x;
+	(void)y;
+	(void)line;
+	(void)lowest;
+	(void)perfect;
 #endif
 		return sector->ceilingheight;
 }
@@ -1015,7 +1037,9 @@ fixed_t P_MobjCeilingZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed
 // Now do the same as all above, but for cameras because apparently cameras are special?
 fixed_t P_CameraFloorZ(camera_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect)
 {
+#ifdef ESLOPE
 	I_Assert(mobj != NULL);
+#endif
 	I_Assert(sector != NULL);
 #ifdef ESLOPE
 	if (sector->f_slope) {
@@ -1087,13 +1111,23 @@ fixed_t P_CameraFloorZ(camera_t *mobj, sector_t *sector, sector_t *boundsec, fix
 
 		return HighestOnLine(mobj->radius, x, y, line, slope, lowest);
 	} else // Well, that makes it easy. Just get the floor height
+#else
+	(void)mobj;
+	(void)boundsec;
+	(void)x;
+	(void)y;
+	(void)line;
+	(void)lowest;
+	(void)perfect;
 #endif
 		return sector->floorheight;
 }
 
 fixed_t P_CameraCeilingZ(camera_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect)
 {
+#ifdef ESLOPE
 	I_Assert(mobj != NULL);
+#endif
 	I_Assert(sector != NULL);
 #ifdef ESLOPE
 	if (sector->c_slope) {
@@ -1165,6 +1199,14 @@ fixed_t P_CameraCeilingZ(camera_t *mobj, sector_t *sector, sector_t *boundsec, f
 
 		return HighestOnLine(mobj->radius, x, y, line, slope, lowest);
 	} else // Well, that makes it easy. Just get the ceiling height
+#else
+	(void)mobj;
+	(void)boundsec;
+	(void)x;
+	(void)y;
+	(void)line;
+	(void)lowest;
+	(void)perfect;
 #endif
 		return sector->ceilingheight;
 }
diff --git a/src/p_saveg.c b/src/p_saveg.c
index e0112bb7..c38a1ebb 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -924,8 +924,12 @@ typedef enum
 	MD2_EXTVAL1     = 1<<5,
 	MD2_EXTVAL2     = 1<<6,
 	MD2_HNEXT       = 1<<7,
+#ifdef ESLOPE
 	MD2_HPREV       = 1<<8,
 	MD2_SLOPE       = 1<<9
+#else
+	MD2_HPREV       = 1<<8
+#endif
 } mobj_diff2_t;
 
 typedef enum
@@ -1115,8 +1119,10 @@ static void SaveMobjThinker(const thinker_t *th, const UINT8 type)
 		diff2 |= MD2_HNEXT;
 	if (mobj->hprev)
 		diff2 |= MD2_HPREV;
+#ifdef ESLOPE
 	if (mobj->standingslope)
 		diff2 |= MD2_SLOPE;
+#endif
 	if (diff2 != 0)
 		diff |= MD_MORE;
 
@@ -1232,8 +1238,10 @@ static void SaveMobjThinker(const thinker_t *th, const UINT8 type)
 		WRITEUINT32(save_p, mobj->hnext->mobjnum);
 	if (diff2 & MD2_HPREV)
 		WRITEUINT32(save_p, mobj->hprev->mobjnum);
+#ifdef ESLOPE
 	if (diff2 & MD2_SLOPE)
 		WRITEUINT16(save_p, mobj->standingslope->id);
+#endif
 
 	WRITEUINT32(save_p, mobj->mobjnum);
 }
@@ -2087,8 +2095,10 @@ static void LoadMobjThinker(actionf_p1 thinker)
 		mobj->hnext = (mobj_t *)(size_t)READUINT32(save_p);
 	if (diff2 & MD2_HPREV)
 		mobj->hprev = (mobj_t *)(size_t)READUINT32(save_p);
+#ifdef ESLOPE
 	if (diff2 & MD2_SLOPE)
 		mobj->standingslope = P_SlopeById(READUINT16(save_p));
+#endif
 
 
 	if (diff & MD_REDFLAG)
diff --git a/src/p_spec.c b/src/p_spec.c
index 76c3484c..a903aa5a 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -4672,8 +4672,10 @@ void P_UpdateSpecials(void)
 	// POINT LIMIT
 	P_CheckPointLimit();
 
+#ifdef ESLOPE
 	// Dynamic slopeness
 	P_RunDynamicSlopes();
+#endif
 
 	// ANIMATE TEXTURES
 	for (anim = anims; anim < lastanim; anim++)
diff --git a/src/r_main.c b/src/r_main.c
index a6b13302..39958305 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -517,7 +517,9 @@ static void R_InitTextureMapping(void)
 	focallength = FixedDiv(centerxfrac,
 		FINETANGENT(FINEANGLES/4+/*cv_fov.value*/ FIELDOFVIEW/2));
 
+#ifdef ESLOPE
 	focallengthf = FIXED_TO_FLOAT(focallength);
+#endif
 
 	for (i = 0; i < FINEANGLES/2; i++)
 	{
diff --git a/src/r_segs.c b/src/r_segs.c
index 6efac902..fd0bde33 100644
--- a/src/r_segs.c
+++ b/src/r_segs.c
@@ -288,7 +288,9 @@ void R_RenderMaskedSegRange(drawseg_t *ds, INT32 x1, INT32 x2)
 	line_t *ldef;
 	sector_t *front, *back;
 	INT32 times, repeats;
+#ifdef ESLOPE
 	INT32 range;
+#endif
 
 	// Calculate light table.
 	// Use different light tables
@@ -335,7 +337,9 @@ void R_RenderMaskedSegRange(drawseg_t *ds, INT32 x1, INT32 x2)
 		colfunc = fuzzcolfunc;
 	}
 
+#ifdef ESLOPE
 	range = max(ds->x2-ds->x1, 1);
+#endif
 	rw_scalestep = ds->scalestep;
 	spryscale = ds->scale1 + (x1 - ds->x1)*rw_scalestep;
 
@@ -695,7 +699,9 @@ void R_RenderThickSideRange(drawseg_t *ds, INT32 x1, INT32 x2, ffloor_t *pfloor)
 	fixed_t         offsetvalue = 0;
 	lightlist_t     *light;
 	r_lightlist_t   *rlight;
+#ifdef ESLOPE
 	INT32           range;
+#endif
 #ifndef ESLOPE
 	fixed_t         lheight;
 #endif
@@ -760,7 +766,9 @@ void R_RenderThickSideRange(drawseg_t *ds, INT32 x1, INT32 x2, ffloor_t *pfloor)
 	else if (pfloor->flags & FF_FOG)
 		colfunc = R_DrawFogColumn_8;
 
+#ifdef ESLOPE
 	range = max(ds->x2-ds->x1, 1);
+#endif
 	//SoM: Moved these up here so they are available for my lightlist calculations
 	rw_scalestep = ds->scalestep;
 	spryscale = ds->scale1 + (x1 - ds->x1)*rw_scalestep;
@@ -1192,7 +1200,9 @@ static void R_RenderSegLoop (void)
 
 	INT32     mid;
 	fixed_t texturecolumn = 0;
+#ifdef ESLOPE
 	fixed_t oldtexturecolumn = -1;
+#endif
 	INT32     top;
 	INT32     bottom;
 	INT32     i;
@@ -1548,7 +1558,9 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 	fixed_t       hyp;
 	fixed_t       sineval;
 	angle_t       distangle, offsetangle;
-	//fixed_t       vtop;
+#ifndef ESLOPE
+	fixed_t       vtop;
+#endif
 	INT32           lightnum;
 	INT32           i, p;
 	lightlist_t   *light;