diff --git a/clang/include/clang/Analysis/Support/BumpVector.h b/clang/include/clang/Analysis/Support/BumpVector.h
index b23a80ed481a25a5cd418377fc1e9371e737025e..48851d0f2637334224b35623f5a9f9c909e2702a 100644
--- a/clang/include/clang/Analysis/Support/BumpVector.h
+++ b/clang/include/clang/Analysis/Support/BumpVector.h
@@ -166,7 +166,7 @@ public:
 private:
   /// grow - double the size of the allocated memory, guaranteeing space for at
   /// least one more element or MinSize if specified.
-  void grow(BumpVectorContext &C, size_type MinSize = 0);
+  void grow(BumpVectorContext &C, size_type MinSize = 1);
   
   void construct_range(T *S, T *E, const T &Elt) {
     for (; S != E; ++S)