diff --git a/lib/Lex/PPLexerChange.cpp b/lib/Lex/PPLexerChange.cpp
index bd0ff7f..c156751 100644
--- a/lib/Lex/PPLexerChange.cpp
+++ b/lib/Lex/PPLexerChange.cpp
@@ -86,7 +86,7 @@
   // left, we can just grow it.  This means we only have to do the new 1/16th as
   // often.
   
-  Token *LookaheadTokens = new Token[N];
+  Token *LookaheadTokens = new Token[N+1];
 
   // Read N+1 tokens into LookaheadTokens.  After this loop, Tok is the token
   // to return.