diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index cc554a91bea..35e98c01760 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4022,21 +4022,28 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
       if (Record.size() != 4)
         return Error("Invalid record");
-      PointerType *Ty =
-        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
-      Type *OpTy = getTypeByID(Record[1]);
-      Value *Size = getFnValueByID(Record[2], OpTy);
       uint64_t AlignRecord = Record[3];
       const uint64_t InAllocaMask = uint64_t(1) << 5;
+      const uint64_t ExplicitTypeMask = uint64_t(1) << 6;
+      const uint64_t FlagMask = InAllocaMask | ExplicitTypeMask;
       bool InAlloca = AlignRecord & InAllocaMask;
+      Type *Ty = getTypeByID(Record[0]);
+      if ((AlignRecord & ExplicitTypeMask) == 0) {
+        auto *PTy = dyn_cast_or_null<PointerType>(Ty);
+        if (!PTy)
+          return Error("Old-style alloca with a non-pointer type");
+        Ty = PTy->getElementType();
+      }
+      Type *OpTy = getTypeByID(Record[1]);
+      Value *Size = getFnValueByID(Record[2], OpTy);
       unsigned Align;
       if (std::error_code EC =
-          parseAlignmentValue(AlignRecord & ~InAllocaMask, Align)) {
+              parseAlignmentValue(AlignRecord & ~FlagMask, Align)) {
         return EC;
       }
       if (!Ty || !Size)
         return Error("Invalid record");
-      AllocaInst *AI = new AllocaInst(Ty->getElementType(), Size, Align);
+      AllocaInst *AI = new AllocaInst(Ty, Size, Align);
       AI->setUsedWithInAlloca(InAlloca);
       I = AI;
       InstructionList.push_back(I);
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b6444b2d060..15b0106ef54 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1870,15 +1870,16 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
 
   case Instruction::Alloca: {
     Code = bitc::FUNC_CODE_INST_ALLOCA;
-    Vals.push_back(VE.getTypeID(I.getType()));
+    const AllocaInst &AI = cast<AllocaInst>(I);
+    Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
-    const AllocaInst &AI = cast<AllocaInst>(I);
     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
            "not enough bits for maximum alignment");
     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
     AlignRecord |= AI.isUsedWithInAlloca() << 5;
+    AlignRecord |= 1 << 6;
     Vals.push_back(AlignRecord);
     break;
   }