diff --git a/src/gui/lua/luainstance.cpp b/src/gui/lua/luainstance.cpp
index ceb0b80ea..dc9576a56 100644
--- a/src/gui/lua/luainstance.cpp
+++ b/src/gui/lua/luainstance.cpp
@@ -636,7 +636,7 @@ void LuaInstRegisterFunctions(lua_State *L, bool fromThreads/*=false*/)
 		{ NULL, NULL }
 	};
 // ------------------------------------------
-	int top;
+	int top = 0;
 	if (fromThreads)
 		top = lua_gettop(L);