diff --git a/Cudd/Imperative.hs b/Cudd/Imperative.hs
index 291f2e2..a8ed3ea 100644
--- a/Cudd/Imperative.hs
+++ b/Cudd/Imperative.hs
@@ -80,8 +80,6 @@ module Cudd.Imperative (
     setMaxCacheHard,
     readCacheSlots,
     readCacheUsedSlots,
-    cudd_unique_slots,
-    cudd_cache_slots,
     andLimit,
     readTree,
     newVarAtLevel,