diff --git a/include/boost/xpressive/detail/core/peeker.hpp b/include/boost/xpressive/detail/core/peeker.hpp
index d7239cc20..e464637c9 100644
--- a/include/boost/xpressive/detail/core/peeker.hpp
+++ b/include/boost/xpressive/detail/core/peeker.hpp
@@ -271,7 +271,6 @@ struct xpression_peeker
 
     hash_peek_bitset<Char> &bset_;
     peeker_string<Char> str_;
-    bool str_icase_;
     bool line_start_;
     void const *traits_;
     std::type_info const *traits_type_;