diff --git a/src/main/resources/assets/computercraft/lua/rom/apis/peripheral.lua b/src/main/resources/assets/computercraft/lua/rom/apis/peripheral.lua
index 9ab5b6fa9..7b8b51dcd 100644
--- a/src/main/resources/assets/computercraft/lua/rom/apis/peripheral.lua
+++ b/src/main/resources/assets/computercraft/lua/rom/apis/peripheral.lua
@@ -105,8 +105,8 @@ function wrap( _sSide )
 end
 
 function find( sType, fnFilter )
-    if type( _sSide ) ~= "string" then
-        error( "bad argument #1 (expected string, got " .. type( _sSide ) .. ")", 2 )
+    if type( sType ) ~= "string" then
+        error( "bad argument #1 (expected string, got " .. type( sType ) .. ")", 2 )
     end
     if fnFilter ~= nil and type( fnFilter ) ~= "string" then
         error( "bad argument #2 (expected function, got " .. type( fnFilter ) .. ")", 2 )