diff --git a/src/dehacked.c b/src/dehacked.c
index 251b0532..d470c7fa 100644
--- a/src/dehacked.c
+++ b/src/dehacked.c
@@ -7261,11 +7261,13 @@ struct {
 	{"FF_COLORMAPONLY",FF_COLORMAPONLY},       ///< Only copy the colormap, not the lightlevel
 	{"FF_GOOWATER",FF_GOOWATER},               ///< Used with ::FF_SWIMMABLE. Makes thick bouncey goop.
 
+#ifdef ESLOPE
 	// Slope flags
 	{"SL_NOPHYSICS",SL_NOPHYSICS},      // Don't do momentum adjustment with this slope
 	{"SL_NODYNAMIC",SL_NODYNAMIC},      // Slope will never need to move during the level, so don't fuss with recalculating it
 	{"SL_ANCHORVERTEX",SL_ANCHORVERTEX},// Slope is using a Slope Vertex Thing to anchor its position
 	{"SL_VERTEXSLOPE",SL_VERTEXSLOPE},  // Slope is built from three Slope Vertex Things
+#endif
 
 	// Angles
 	{"ANG1",ANG1},
diff --git a/src/lua_libs.h b/src/lua_libs.h
index a9c82bce..15d988ef 100644
--- a/src/lua_libs.h
+++ b/src/lua_libs.h
@@ -38,9 +38,11 @@ extern lua_State *gL;
 #define META_SUBSECTOR "SUBSECTOR_T*"
 #define META_SECTOR "SECTOR_T*"
 #define META_FFLOOR "FFLOOR_T*"
+#ifdef ESLOPE
 #define META_SLOPE "PSLOPE_T*"
 #define META_VECTOR2 "VECTOR2_T"
 #define META_VECTOR3 "VECTOR3_T"
+#endif
 #define META_MAPHEADER "MAPHEADER_T*"
 
 #define META_CVAR "CONSVAR_T*"
diff --git a/src/lua_maplib.c b/src/lua_maplib.c
index 7635ded1..d8363429 100644
--- a/src/lua_maplib.c
+++ b/src/lua_maplib.c
@@ -40,10 +40,14 @@ enum sector_e {
 	sector_heightsec,
 	sector_camsec,
 	sector_lines,
+#ifdef ESLOPE
 	sector_ffloors,
 	sector_fslope,
 	sector_cslope,
 	sector_hasslope
+#else
+	sector_ffloors
+#endif
 };
 
 static const char *const sector_opt[] = {
@@ -60,9 +64,11 @@ static const char *const sector_opt[] = {
 	"camsec",
 	"lines",
 	"ffloors",
+#ifdef ESLOPE
 	"f_slope",
 	"c_slope",
 	"hasslope",
+#endif
 	NULL};
 
 enum subsector_e {
@@ -168,8 +174,10 @@ enum ffloor_e {
 	ffloor_toplightlevel,
 	ffloor_bottomheight,
 	ffloor_bottompic,
+#ifdef ESLOPE
 	ffloor_tslope,
 	ffloor_bslope,
+#endif
 	ffloor_sector,
 	ffloor_flags,
 	ffloor_master,
@@ -186,8 +194,10 @@ static const char *const ffloor_opt[] = {
 	"toplightlevel",
 	"bottomheight",
 	"bottompic",
+#ifdef ESLOPE
 	"t_slope",
 	"b_slope",
+#endif
 	"sector", // secnum pushed as control sector userdata
 	"flags",
 	"master", // control linedef
@@ -197,6 +207,7 @@ static const char *const ffloor_opt[] = {
 	"alpha",
 	NULL};
 
+#ifdef ESLOPE
 enum slope_e {
 	slope_valid = 0,
 	slope_o,
@@ -235,6 +246,7 @@ static const char *const vector_opt[] = {
 	"y",
 	"z",
 	NULL};
+#endif
 
 static const char *const array_opt[] ={"iterate",NULL};
 static const char *const valid_opt[] ={"valid",NULL};
@@ -450,6 +462,7 @@ static int sector_get(lua_State *L)
 		LUA_PushUserdata(L, sector->ffloors, META_FFLOOR);
 		lua_pushcclosure(L, sector_iterate, 2); // push lib_iterateFFloors and sector->ffloors as upvalues for the function
 		return 1;
+#ifdef ESLOPE
 	case sector_fslope: // f_slope
 		LUA_PushUserdata(L, sector->f_slope, META_SLOPE);
 		return 1;
@@ -459,6 +472,7 @@ static int sector_get(lua_State *L)
 	case sector_hasslope: // hasslope
 		lua_pushboolean(L, sector->hasslope);
 		return 1;
+#endif
 	}
 	return 0;
 }
@@ -481,9 +495,11 @@ static int sector_set(lua_State *L)
 	case sector_heightsec: // heightsec
 	case sector_camsec: // camsec
 	case sector_ffloors: // ffloors
+#ifdef ESLOPE
 	case sector_fslope: // f_slope
 	case sector_cslope: // c_slope
 	case sector_hasslope: // hasslope
+#endif
 	default:
 		return luaL_error(L, "sector_t field " LUA_QS " cannot be set.", sector_opt[field]);
 	case sector_floorheight: { // floorheight
@@ -1118,12 +1134,14 @@ static int ffloor_get(lua_State *L)
 		lua_pushlstring(L, levelflat->name, 8);
 		return 1;
 	}
+#ifdef ESLOPE
 	case ffloor_tslope:
 		LUA_PushUserdata(L, *ffloor->t_slope, META_SLOPE);
 		return 1;
 	case ffloor_bslope:
 		LUA_PushUserdata(L, *ffloor->b_slope, META_SLOPE);
 		return 1;
+#endif
 	case ffloor_sector:
 		LUA_PushUserdata(L, &sectors[ffloor->secnum], META_SECTOR);
 		return 1;
@@ -1163,8 +1181,10 @@ static int ffloor_set(lua_State *L)
 	switch(field)
 	{
 	case ffloor_valid: // valid
+#ifdef ESLOPE
 	case ffloor_tslope: // t_slope
 	case ffloor_bslope: // b_slope
+#endif
 	case ffloor_sector: // sector
 	case ffloor_master: // master
 	case ffloor_target: // target
@@ -1225,6 +1245,7 @@ static int ffloor_set(lua_State *L)
 	return 0;
 }
 
+#ifdef ESLOPE
 static int slope_get(lua_State *L)
 {
 	pslope_t *slope = *((pslope_t **)luaL_checkudata(L, 1, META_SLOPE));
@@ -1391,6 +1412,7 @@ static int vector3_get(lua_State *L)
 
 	return 0;
 }
+#endif
 
 static int lib_getMapheaderinfo(lua_State *L)
 {
@@ -1568,6 +1590,7 @@ int LUA_MapLib(lua_State *L)
 		lua_setfield(L, -2, "__newindex");
 	lua_pop(L, 1);
 
+#ifdef ESLOPE
 	luaL_newmetatable(L, META_SLOPE);
 		lua_pushcfunction(L, slope_get);
 		lua_setfield(L, -2, "__index");
@@ -1585,6 +1608,7 @@ int LUA_MapLib(lua_State *L)
 		lua_pushcfunction(L, vector3_get);
 		lua_setfield(L, -2, "__index");
 	lua_pop(L, 1);
+#endif
 
 	luaL_newmetatable(L, META_MAPHEADER);
 		lua_pushcfunction(L, mapheaderinfo_get);