diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.h b/llvm/lib/Bitcode/Reader/BitcodeReader.h
index c7c6152..3935ebbf 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.h
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.h
@@ -58,6 +58,7 @@
   BitcodeReaderValueList ValueList;
   std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
 public:
+  BitcodeReader() : ErrorString(0) {}
   virtual ~BitcodeReader() {}
   
   virtual void FreeState() {}