diff --git a/src/auto4_lua_assfile.cpp b/src/auto4_lua_assfile.cpp
index 3aef3b769..f98e0a35d 100644
--- a/src/auto4_lua_assfile.cpp
+++ b/src/auto4_lua_assfile.cpp
@@ -40,6 +40,7 @@
 #include "ass_karaoke.h"
 #include "ass_style.h"
 #include "compat.h"
+#include "fold_controller.h"
 
 #include <libaegisub/exception.h>
 #include <libaegisub/log.h>
@@ -100,6 +101,16 @@ namespace {
 		return ret;
 	}
 
+	template<typename T>
+	void get_userdata_field(lua_State *L, const char *name, const char *line_class, T *target)
+	{
+		lua_getfield(L, -1, name);
+		if (!lua_isuserdata(L, -1))
+			throw bad_field("userdata", name, line_class);
+		*target = *static_cast<T *>(lua_touserdata(L, -1));
+		lua_pop(L, 1);
+	}
+
 	using namespace Automation4;
 	template<int (LuaAssFile::*closure)(lua_State *)>
 	int closure_wrapper(lua_State *L)
@@ -181,6 +192,10 @@ namespace Automation4 {
 
 			set_field(L, "text", dia->Text);
 
+			// preserve the folds
+			*static_cast<FoldInfo*>(lua_newuserdata(L, sizeof(FoldInfo))) = dia->Fold;
+			lua_setfield(L, -2, "_foldinfo");
+
 			// create extradata table
 			lua_newtable(L);
 			for (auto const& ed : ass->GetExtradata(dia->ExtradataIds)) {
@@ -301,6 +316,7 @@ namespace Automation4 {
 			dia->Margin[2] = get_int_field(L, "margin_t", "dialogue");
 			dia->Effect = get_string_field(L, "effect", "dialogue");
 			dia->Text = get_string_field(L, "text", "dialogue");
+			get_userdata_field(L, "_foldinfo", "dialogue", &dia->Fold);
 
 			std::vector<uint32_t> new_ids;