diff --git a/MCServer/Plugins/APIDump/main_APIDump.lua b/MCServer/Plugins/APIDump/main_APIDump.lua
index 4ca06b974..e841922b6 100644
--- a/MCServer/Plugins/APIDump/main_APIDump.lua
+++ b/MCServer/Plugins/APIDump/main_APIDump.lua
@@ -971,7 +971,7 @@ end
 
 --- Writes a list of undocumented objects into a file
 local function ListUndocumentedObjects(API, UndocumentedHooks)
-	f = io.open("API/_undocumented.lua", "w");
+	local f = io.open("API/_undocumented.lua", "w");
 	if (f ~= nil) then
 		f:write("\n-- This is the list of undocumented API objects, automatically generated by APIDump\n\n");
 		f:write("g_APIDesc =\n{\n\tClasses =\n\t{\n");