diff --git a/checks/Check.hs b/checks/Check.hs
index 111a001..ded4c82 100644
--- a/checks/Check.hs
+++ b/checks/Check.hs
@@ -571,5 +571,5 @@ checkUnusedVar = forAnyASTStructBottomUpAccum doSpec
                when (not $ A.nameName name `elem` map A.nameName usedNames) $
                 do warnPC mspec WarnUnusedVariable $ formatCode "Unused variable: %" name
                    modify (\st -> st { csNames = Map.delete (A.nameName name) (csNames st) })
-                   substitute scope
+                   -- substitute scope
     doSpec _ = return ()
diff --git a/pass/PassList.hs b/pass/PassList.hs
index b601a72..11e53d6 100644
--- a/pass/PassList.hs
+++ b/pass/PassList.hs
@@ -68,8 +68,8 @@ commonPasses opts = concat $
   , enablePassesWhen csUsageChecking
      [abbrevCheckPass]
   , backendPasses
---  , [pass "Removing unused variables" [] []
---      (passOnlyOnAST "checkUnusedVar" (runChecks checkUnusedVar))]
+  , [pass "Removing unused variables" [] []
+      (passOnlyOnAST "checkUnusedVar" (runChecks checkUnusedVar))]
   ]
 
 filterPasses :: CompState -> [Pass t] -> [Pass t]