diff --git a/wcclrun/main.cpp b/wcclrun/main.cpp
index c9181232a72fd4b21919da35ef2c2dd6233a98d9..236731913526bcf29e4723df4c5c64da7a97d9df 100644
--- a/wcclrun/main.cpp
+++ b/wcclrun/main.cpp
@@ -89,7 +89,7 @@ void do_sentence(const boost::shared_ptr<Corpus2::Sentence>& sentence,
 {
 	Wccl::SentenceContext sc(sentence);
 	std::vector< std::vector< UnicodeString > > outputs(sentence->size());
-	std::vector<int> lengths(ops.size(), 0);
+	std::vector<int> lengths(ops.size() + 1, 0);
 	streamsave sv(std::cout);
 	for (size_t i = 0; i < sentence->size(); ++i) {
 		sc.set_position(i);