diff --git a/spritesheet.lua b/spritesheet.lua
index 9ef9dba..154ae6f 100644
--- a/spritesheet.lua
+++ b/spritesheet.lua
@@ -3,8 +3,9 @@
 --- Has support for both individual images in spritesheets and animations. This
 --- can be specified from a lua file placed beside the spritesheet image file.
 
+local error_original = error
 local error, error_internal do
-    error, error_internal  =  error, error
+    error, error_internal  =  error_original, error_original
     local success, errorlib = pcall(require, 'errors')
     if success then
         error = errorlib 'spritesheet'