diff --git a/aegisub/build/Aegisub/Aegisub.vcxproj b/aegisub/build/Aegisub/Aegisub.vcxproj
index b40534193..69ec6704e 100644
--- a/aegisub/build/Aegisub/Aegisub.vcxproj
+++ b/aegisub/build/Aegisub/Aegisub.vcxproj
@@ -134,6 +134,7 @@
     <ClInclude Include="$(SrcDir)auto4_lua.h" />
     <ClInclude Include="$(SrcDir)auto4_lua_factory.h" />
     <ClInclude Include="$(SrcDir)auto4_lua_scriptreader.h" />
+    <ClInclude Include="$(SrcDir)auto4_lua_utils.h" />
     <ClInclude Include="$(SrcDir)avisynth.h" />
     <ClInclude Include="$(SrcDir)avisynth_wrap.h" />
     <ClInclude Include="$(SrcDir)base_grid.h" />
diff --git a/aegisub/build/Aegisub/Aegisub.vcxproj.filters b/aegisub/build/Aegisub/Aegisub.vcxproj.filters
index 3b718bcc5..e7b2dd773 100644
--- a/aegisub/build/Aegisub/Aegisub.vcxproj.filters
+++ b/aegisub/build/Aegisub/Aegisub.vcxproj.filters
@@ -687,6 +687,9 @@
     <ClInclude Include="$(SrcDir)subs_controller.h">
       <Filter>ASS</Filter>
     </ClInclude>
+    <ClInclude Include="$(SrcDir)auto4_lua_utils.h">
+      <Filter>Automation\Lua</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(SrcDir)ass_dialogue.cpp">
diff --git a/aegisub/src/auto4_lua.cpp b/aegisub/src/auto4_lua.cpp
index c41287c4b..60633aa3f 100644
--- a/aegisub/src/auto4_lua.cpp
+++ b/aegisub/src/auto4_lua.cpp
@@ -38,6 +38,7 @@
 
 #include "auto4_lua.h"
 
+#include "auto4_lua_utils.h"
 #include "ass_dialogue.h"
 #include "ass_file.h"
 #include "ass_style.h"
@@ -53,8 +54,6 @@
 #include "utils.h"
 
 #include <libaegisub/access.h>
-#include <libaegisub/fs.h>
-#include <libaegisub/log.h>
 #include <libaegisub/path.h>
 #include <libaegisub/scoped_ptr.h>
 
@@ -75,78 +74,7 @@
 #include <wx/regex.h>
 #include <wx/window.h>
 
-// This must be below the headers above.
-#ifdef __WINDOWS__
-#include "../../contrib/lua51/src/lualib.h"
-#include "../../contrib/lua51/src/lauxlib.h"
-#else
-#include <lua.hpp>
-#endif
-
 namespace {
-	inline void push_value(lua_State *L, lua_CFunction fn) {
-		lua_pushcfunction(L, fn);
-	}
-
-	inline void push_value(lua_State *L, int n) {
-		lua_pushinteger(L, n);
-	}
-
-	inline void push_value(lua_State *L, void *p) {
-		lua_pushlightuserdata(L, p);
-	}
-
-	inline void push_value(lua_State *L, agi::fs::path const& p) {
-		lua_pushstring(L, p.string().c_str());
-	}
-
-	inline void push_value(lua_State *L, wxString const& s) {
-		lua_pushstring(L, s.utf8_str());
-	}
-
-	inline void push_value(lua_State *L, std::string const& s) {
-		lua_pushstring(L, s.c_str());
-	}
-
-	inline void push_value(lua_State *L, const char *s) {
-		lua_pushstring(L, s);
-	}
-
-	template<class T>
-	inline void set_field(lua_State *L, const char *name, T value)
-	{
-		push_value(L, value);
-		lua_setfield(L, -2, name);
-	}
-
-	inline wxString get_wxstring(lua_State *L, int idx)
-	{
-		return wxString::FromUTF8(lua_tostring(L, idx));
-	}
-
-	inline wxString check_wxstring(lua_State *L, int idx)
-	{
-		return wxString::FromUTF8(luaL_checkstring(L, idx));
-	}
-
-	std::string get_string_or_default(lua_State *L, int idx)
-	{
-		const char *str = lua_tostring(L, idx);
-		if (!str)
-			str = "<not a string>";
-		return str;
-	}
-
-	std::string get_global_string(lua_State *L, const char *name)
-	{
-		lua_getglobal(L, name);
-		std::string ret;
-		if (lua_isstring(L, -1))
-			ret = lua_tostring(L, -1);
-		lua_pop(L, 1);
-		return ret;
-	}
-
 	void set_context(lua_State *L, const agi::Context *c)
 	{
 		// Explicit cast is needed to discard the const
@@ -345,47 +273,6 @@ namespace {
 	}
 }
 
-	// LuaStackcheck
-#ifdef _DEBUG
-	struct LuaStackcheck {
-		lua_State *L;
-		int startstack;
-		void check_stack(int additional)
-		{
-			int top = lua_gettop(L);
-			if (top - additional != startstack) {
-				LOG_D("automation/lua") << "lua stack size mismatch.";
-				dump();
-				assert(top - additional == startstack);
-			}
-		}
-		void dump()
-		{
-			int top = lua_gettop(L);
-			LOG_D("automation/lua/stackdump") << "--- dumping lua stack...";
-			for (int i = top; i > 0; i--) {
-				lua_pushvalue(L, i);
-				std::string type(lua_typename(L, lua_type(L, -1)));
-				if (lua_isstring(L, i)) {
-					LOG_D("automation/lua/stackdump") << type << ": " << lua_tostring(L, -1);
-				} else {
-					LOG_D("automation/lua/stackdump") << type;
-				}
-				lua_pop(L, 1);
-			}
-			LOG_D("automation/lua") << "--- end dump";
-		}
-		LuaStackcheck(lua_State *L) : L(L) { startstack = lua_gettop(L); }
-		~LuaStackcheck() { check_stack(0); }
-	};
-#else
-	struct LuaStackcheck {
-		void check_stack(int) { }
-		void dump() { }
-		LuaStackcheck(lua_State*) { }
-	};
-#endif
-
 namespace Automation4 {
 	// LuaScript
 	LuaScript::LuaScript(agi::fs::path const& filename)
diff --git a/aegisub/src/auto4_lua_assfile.cpp b/aegisub/src/auto4_lua_assfile.cpp
index 07e7b87af..9c8883009 100644
--- a/aegisub/src/auto4_lua_assfile.cpp
+++ b/aegisub/src/auto4_lua_assfile.cpp
@@ -37,6 +37,7 @@
 #ifdef WITH_AUTO4_LUA
 #include "auto4_lua.h"
 
+#include "auto4_lua_utils.h"
 #include "ass_dialogue.h"
 #include "ass_info.h"
 #include "ass_file.h"
@@ -45,7 +46,6 @@
 #include "utils.h"
 
 #include <libaegisub/exception.h>
-#include <libaegisub/log.h>
 #include <libaegisub/scoped_ptr.h>
 
 #include <algorithm>
@@ -54,48 +54,7 @@
 #include <boost/range/algorithm_ext.hpp>
 #include <cassert>
 
-// This must be below the headers above.
-#ifdef __WINDOWS__
-#include "../../contrib/lua51/src/lualib.h"
-#include "../../contrib/lua51/src/lauxlib.h"
-#else
-#include <lua.hpp>
-#endif
-
 namespace {
-	void push_value(lua_State *L, std::string const& value) {
-		lua_pushstring(L, value.c_str());
-	}
-
-	void push_value(lua_State *L, const char *value) {
-		lua_pushstring(L, value);
-	}
-
-	// Userdata object must be just above the target table
-	void push_value(lua_State *L, lua_CFunction value) {
-		assert(lua_type(L, -2) == LUA_TUSERDATA);
-		lua_pushvalue(L, -2);
-		lua_pushcclosure(L, value, 1);
-	}
-
-	void push_value(lua_State *L, bool value) {
-		lua_pushboolean(L, value);
-	}
-
-	void push_value(lua_State *L, double value) {
-		lua_pushnumber(L, value);
-	}
-
-	void push_value(lua_State *L, int value) {
-		lua_pushinteger(L, value);
-	}
-
-	template<typename T>
-	void set_field(lua_State *L, const char *name, T value) {
-		push_value(L, value);
-		lua_setfield(L, -2, name);
-	}
-
 	DEFINE_SIMPLE_EXCEPTION_NOINNER(BadField, Automation4::MacroRunError, "automation/macro/bad_field")
 	BadField bad_field(const char *expected_type, const char *name, const char *line_clasee)
 	{
diff --git a/aegisub/src/auto4_lua_progresssink.cpp b/aegisub/src/auto4_lua_progresssink.cpp
index 76be20477..56191e2a8 100644
--- a/aegisub/src/auto4_lua_progresssink.cpp
+++ b/aegisub/src/auto4_lua_progresssink.cpp
@@ -35,17 +35,11 @@
 #include "config.h"
 
 #ifdef WITH_AUTO4_LUA
-
 #include "auto4_lua.h"
 
-#include <wx/filedlg.h>
+#include "auto4_lua_utils.h"
 
-#ifdef __WINDOWS__
-#include "../../contrib/lua51/src/lua.h"
-#include "../../contrib/lua51/src/lauxlib.h"
-#else
-#include <lua.hpp>
-#endif
+#include <wx/filedlg.h>
 
 namespace {
 	void set_field_to_closure(lua_State *L, const char *name, lua_CFunction fn, int ps_idx = -3)
@@ -60,11 +54,6 @@ namespace {
 		lua_pushnil(L);
 		lua_setfield(L, idx, name);
 	}
-
-	inline wxString check_wxstring(lua_State *L, int idx)
-	{
-		return wxString::FromUTF8(luaL_checkstring(L, idx));
-	}
 }
 
 namespace Automation4 {
diff --git a/aegisub/src/auto4_lua_utils.h b/aegisub/src/auto4_lua_utils.h
new file mode 100644
index 000000000..607d3d32b
--- /dev/null
+++ b/aegisub/src/auto4_lua_utils.h
@@ -0,0 +1,126 @@
+// Copyright (c) 2012, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// Aegisub Project http://www.aegisub.org/
+
+#include <libaegisub/log.h>
+
+#ifdef __WINDOWS__
+#include "../../contrib/lua51/src/lualib.h"
+#include "../../contrib/lua51/src/lauxlib.h"
+#else
+#include <lua.hpp>
+#endif
+
+#include <libaegisub/fs.h>
+
+#include <string>
+#include <wx/string.h>
+
+inline void push_value(lua_State *L, bool value) { lua_pushboolean(L, value); }
+inline void push_value(lua_State *L, const char *value) { lua_pushstring(L, value); }
+inline void push_value(lua_State *L, double value) { lua_pushnumber(L, value); }
+inline void push_value(lua_State *L, int value) { lua_pushinteger(L, value); }
+inline void push_value(lua_State *L, size_t value) { lua_pushinteger(L, value); }
+inline void push_value(lua_State *L, void *p) { lua_pushlightuserdata(L, p); }
+
+inline void push_value(lua_State *L, wxString const& value) {
+	lua_pushstring(L, value.utf8_str());
+}
+
+inline void push_value(lua_State *L, agi::fs::path const& value) {
+	lua_pushstring(L, value.string().c_str());
+}
+
+inline void push_value(lua_State *L, std::string const& value) {
+	lua_pushstring(L, value.c_str());
+}
+
+inline void push_value(lua_State *L, lua_CFunction value) {
+	if (lua_type(L, -2) == LUA_TUSERDATA) {
+		lua_pushvalue(L, -2);
+		lua_pushcclosure(L, value, 1);
+	}
+	else
+		lua_pushcclosure(L, value, 0);
+}
+
+template<typename T>
+inline void set_field(lua_State *L, const char *name, T value) {
+	push_value(L, value);
+	lua_setfield(L, -2, name);
+}
+
+inline wxString get_wxstring(lua_State *L, int idx) {
+	return wxString::FromUTF8(lua_tostring(L, idx));
+}
+
+inline wxString check_wxstring(lua_State *L, int idx) {
+	return wxString::FromUTF8(luaL_checkstring(L, idx));
+}
+
+inline std::string get_string_or_default(lua_State *L, int idx) {
+	const char *str = lua_tostring(L, idx);
+	if (!str)
+		str = "<not a string>";
+	return str;
+}
+
+inline std::string get_global_string(lua_State *L, const char *name) {
+	lua_getglobal(L, name);
+	std::string ret;
+	if (lua_isstring(L, -1))
+		ret = lua_tostring(L, -1);
+	lua_pop(L, 1);
+	return ret;
+}
+
+#ifdef _DEBUG
+struct LuaStackcheck {
+	lua_State *L;
+	int startstack;
+
+	void check_stack(int additional) {
+		int top = lua_gettop(L);
+		if (top - additional != startstack) {
+			LOG_D("automation/lua") << "lua stack size mismatch.";
+			dump();
+			assert(top - additional == startstack);
+		}
+	}
+
+	void dump() {
+		int top = lua_gettop(L);
+		LOG_D("automation/lua/stackdump") << "--- dumping lua stack...";
+		for (int i = top; i > 0; i--) {
+			lua_pushvalue(L, i);
+			std::string type(lua_typename(L, lua_type(L, -1)));
+			if (lua_isstring(L, i))
+				LOG_D("automation/lua/stackdump") << type << ": " << lua_tostring(L, -1);
+			else
+				LOG_D("automation/lua/stackdump") << type;
+			lua_pop(L, 1);
+		}
+		LOG_D("automation/lua") << "--- end dump";
+	}
+	LuaStackcheck(lua_State *L) : L(L), startstack(lua_gettop(L)) { }
+	~LuaStackcheck() { check_stack(0); }
+};
+#else
+struct LuaStackcheck {
+	void check_stack(int) { }
+	void dump() { }
+	LuaStackcheck(lua_State*) { }
+};
+#endif