diff --git a/include/llvm/BasicBlock.h b/include/llvm/BasicBlock.h
index 3ef83e8a816..54f3690096e 100644
--- a/include/llvm/BasicBlock.h
+++ b/include/llvm/BasicBlock.h
@@ -38,14 +38,14 @@ template<> struct ilist_traits<Instruction>
     // NodeTy, which becomes the sentinel. Dereferencing the sentinel is
     // forbidden (save the ilist_node<NodeTy>) so no one will ever notice
     // the superposition.
-    return const_cast<Instruction*>(static_cast<const Instruction*>(&Sentinel));
+    return static_cast<Instruction*>(&Sentinel);
   }
   static void destroySentinel(Instruction*) {}
   static iplist<Instruction> &getList(BasicBlock *BB);
   static ValueSymbolTable *getSymTab(BasicBlock *ItemParent);
   static int getListOffset();
 private:
-  ilist_node<Instruction> Sentinel;
+  mutable ilist_node<Instruction> Sentinel;
 };
 
 /// This represents a single basic block in LLVM. A basic block is simply a
diff --git a/include/llvm/Function.h b/include/llvm/Function.h
index 9f4f23be088..37e8f19f625 100644
--- a/include/llvm/Function.h
+++ b/include/llvm/Function.h
@@ -35,28 +35,28 @@ template<> struct ilist_traits<BasicBlock>
   // createSentinel is used to get hold of the node that marks the end of the
   // list... (same trick used here as in ilist_traits<Instruction>)
   BasicBlock *createSentinel() const {
-    return const_cast<BasicBlock*>(static_cast<const BasicBlock*>(&Sentinel));
+    return static_cast<BasicBlock*>(&Sentinel);
   }
   static void destroySentinel(BasicBlock*) {}
   static iplist<BasicBlock> &getList(Function *F);
   static ValueSymbolTable *getSymTab(Function *ItemParent);
   static int getListOffset();
 private:
-  ilist_node<BasicBlock> Sentinel;
+  mutable ilist_node<BasicBlock> Sentinel;
 };
 
 template<> struct ilist_traits<Argument>
   : public SymbolTableListTraits<Argument, Function> {
 
   Argument *createSentinel() const {
-    return const_cast<Argument*>(static_cast<const Argument*>(&Sentinel));
+    return static_cast<Argument*>(&Sentinel);
   }
   static void destroySentinel(Argument*) {}
   static iplist<Argument> &getList(Function *F);
   static ValueSymbolTable *getSymTab(Function *ItemParent);
   static int getListOffset();
 private:
-  ilist_node<Argument> Sentinel;
+  mutable ilist_node<Argument> Sentinel;
 };
 
 class Function : public GlobalValue, public Annotable,