diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index c5f847be6..240591506 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -2494,6 +2494,17 @@ static int lib_pGetZAt(lua_State *L)
 	return 1;
 }
 
+static int lib_pButteredSlope(lua_State *L)
+{
+	mobj_t *mobj = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
+	NOHUD
+	INLEVEL
+	if (!mobj)
+		return LUA_ErrInvalid(L, "mobj_t");
+	P_ButteredSlope(mobj);
+	return 0;
+}
+
 // R_DEFS
 ////////////
 
@@ -3932,6 +3943,7 @@ static luaL_Reg lib[] = {
 
 	// p_slopes
 	{"P_GetZAt",lib_pGetZAt},
+	{"P_ButteredSlope",lib_pButteredSlope},
 
 	// r_defs
 	{"R_PointToAngle",lib_rPointToAngle},