diff --git a/include/llvm/IR/Attributes.h b/include/llvm/IR/Attributes.h
index c801436910d..1cd879361cf 100644
--- a/include/llvm/IR/Attributes.h
+++ b/include/llvm/IR/Attributes.h
@@ -346,7 +346,7 @@ public:
   unsigned getNumSlots() const;
 
   /// \brief Return the index for the given slot.
-  uint64_t getSlotIndex(unsigned Slot) const;
+  unsigned getSlotIndex(unsigned Slot) const;
 
   /// \brief Return the attributes at the given slot.
   AttributeSet getSlotAttributes(unsigned Slot) const;
diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index b17aa43b2f3..2f7b4491b23 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -228,7 +228,7 @@ public:
   /// is the index of the return, parameter, or function object that the
   /// attributes are applied to, not the index into the AttrNodes list where the
   /// attributes reside.
-  uint64_t getSlotIndex(unsigned Slot) const {
+  unsigned getSlotIndex(unsigned Slot) const {
     return AttrNodes[Slot].first;
   }
 
@@ -270,7 +270,7 @@ public:
   }
 
   // FIXME: This atrocity is temporary.
-  uint64_t Raw(uint64_t Index) const;
+  uint64_t Raw(unsigned Index) const;
 };
 
 } // end llvm namespace
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 065f7725cc8..2443b3401d4 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -501,7 +501,7 @@ std::string AttributeSetNode::getAsString(bool TargetIndependent,
 // AttributeSetImpl Definition
 //===----------------------------------------------------------------------===//
 
-uint64_t AttributeSetImpl::Raw(uint64_t Index) const {
+uint64_t AttributeSetImpl::Raw(unsigned Index) const {
   for (unsigned I = 0, E = getNumAttributes(); I != E; ++I) {
     if (getSlotIndex(I) != Index) continue;
     const AttributeSetNode *ASN = AttrNodes[I].second;
@@ -889,7 +889,7 @@ unsigned AttributeSet::getNumSlots() const {
   return pImpl ? pImpl->getNumAttributes() : 0;
 }
 
-uint64_t AttributeSet::getSlotIndex(unsigned Slot) const {
+unsigned AttributeSet::getSlotIndex(unsigned Slot) const {
   assert(pImpl && Slot < pImpl->getNumAttributes() &&
          "Slot # out of range!");
   return pImpl->getSlotIndex(Slot);