diff --git a/src/lua_mobjlib.c b/src/lua_mobjlib.c
index 6bb1388f..05091f12 100644
--- a/src/lua_mobjlib.c
+++ b/src/lua_mobjlib.c
@@ -80,7 +80,12 @@ enum mobj_e {
 	mobj_extravalue1,
 	mobj_extravalue2,
 	mobj_cusval,
+#ifdef ESLOPE
+	mobj_cvmem,
+	mobj_standingslope
+#else
 	mobj_cvmem
+#endif
 };
 
 static const char *const mobj_opt[] = {
@@ -140,6 +145,9 @@ static const char *const mobj_opt[] = {
 	"extravalue2",
 	"cusval",
 	"cvmem",
+#ifdef ESLOPE
+	"standingslope",
+#endif
 	NULL};
 
 #define UNIMPLEMENTED luaL_error(L, LUA_QL("mobj_t") " field " LUA_QS " is not implemented for Lua and cannot be accessed.", mobj_opt[field])
@@ -343,6 +351,11 @@ static int mobj_get(lua_State *L)
 	case mobj_cvmem:
 		lua_pushinteger(L, mo->cvmem);
 		break;
+#ifdef ESLOPE
+	case mobj_standingslope:
+		LUA_PushUserdata(L, mo->standingslope, META_SLOPE);
+		break;
+#endif
 	default: // extra custom variables in Lua memory
 		lua_getfield(L, LUA_REGISTRYINDEX, LREG_EXTVARS);
 		I_Assert(lua_istable(L, -1));
@@ -634,6 +647,10 @@ static int mobj_set(lua_State *L)
 	case mobj_cvmem:
 		mo->cvmem = luaL_checkinteger(L, 3);
 		break;
+#ifdef ESLOPE
+	case mobj_standingslope:
+		return NOSET;
+#endif
 	default:
 		lua_getfield(L, LUA_REGISTRYINDEX, LREG_EXTVARS);
 		I_Assert(lua_istable(L, -1));