diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 4808cd48d54..3e8a93aafcb 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -300,7 +300,7 @@ public:
   /// If there is no vector type that we want to widen to, returns MVT::Other
   /// When and were to widen is target dependent based on the cost of
   /// scalarizing vs using the wider vector type.
-  virtual MVT getWidenVectorType(MVT VT);
+  virtual MVT getWidenVectorType(MVT VT) const;
 
   typedef std::vector<APFloat>::const_iterator legal_fpimm_iterator;
   legal_fpimm_iterator legal_fpimm_begin() const {
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 00405ab4f6a..9499a9de6cc 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8036,7 +8036,7 @@ X86TargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
 /// When and where to widen is target dependent based on the cost of
 /// scalarizing vs using the wider vector type.
 
-MVT X86TargetLowering::getWidenVectorType(MVT VT) {
+MVT X86TargetLowering::getWidenVectorType(MVT VT) const {
   assert(VT.isVector());
   if (isTypeLegal(VT))
     return VT;
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 46005d06947..ea9c9311692 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -499,7 +499,7 @@ namespace llvm {
     /// If there is no vector type that we want to widen to, returns MVT::Other
     /// When and were to widen is target dependent based on the cost of
     /// scalarizing vs using the wider vector type.
-    virtual MVT getWidenVectorType(MVT VT);
+    virtual MVT getWidenVectorType(MVT VT) const;
 
     /// createFastISel - This method returns a target specific FastISel object,
     /// or null if the target does not support "fast" ISel.