Index: llvm/include/llvm/CodeGen/MachineRegisterInfo.h
===================================================================
--- llvm/include/llvm/CodeGen/MachineRegisterInfo.h
+++ llvm/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -1008,10 +1008,10 @@
     }
 
   public:
-    using reference = std::iterator<std::forward_iterator_tag,
-                                    MachineInstr, ptrdiff_t>::reference;
-    using pointer = std::iterator<std::forward_iterator_tag,
-                                  MachineInstr, ptrdiff_t>::pointer;
+    using reference = std::iterator<std::forward_iterator_tag, MachineOperand,
+                                    ptrdiff_t>::reference;
+    using pointer = std::iterator<std::forward_iterator_tag, MachineOperand,
+                                  ptrdiff_t>::pointer;
 
     defusechain_iterator() = default;