diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 5c284b746de..27676562d4d 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -637,7 +637,7 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
   case Instruction::SIToFP:
     if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
       APInt api = CI->getValue();
-      APFloat apf(APInt::getNullValue(DestTy->getPrimitiveSizeInBits()));
+      APFloat apf(APInt::getNullValue(DestTy->getPrimitiveSizeInBits()), true);
       (void)apf.convertFromAPInt(api, 
                                  opc==Instruction::SIToFP,
                                  APFloat::rmNearestTiesToEven);
diff --git a/unittests/VMCore/ConstantsTest.cpp b/unittests/VMCore/ConstantsTest.cpp
index 8f28407b8de..8277584ba24 100644
--- a/unittests/VMCore/ConstantsTest.cpp
+++ b/unittests/VMCore/ConstantsTest.cpp
@@ -109,5 +109,14 @@ TEST(ConstantsTest, IntSigns) {
   EXPECT_EQ(0x3b, ConstantInt::get(Int8Ty, 0x13b)->getSExtValue());
 }
 
+TEST(ConstantsTest, FP128Test) {
+  const Type *FP128Ty = Type::getFP128Ty(getGlobalContext());
+
+  const IntegerType *Int128Ty = Type::getIntNTy(getGlobalContext(), 128);
+  Constant *Zero128 = Constant::getNullValue(Int128Ty);
+  Constant *X = ConstantExpr::getUIToFP(Zero128, FP128Ty);
+  EXPECT_TRUE(isa<ConstantFP>(X));
+}
+
 }  // end anonymous namespace
 }  // end namespace llvm