diff --git a/configure.ac b/configure.ac
index fcc4d07..2cfae4b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -60,7 +60,7 @@ AC_COMPILE_IFELSE(
 )
 YAZ_DOC
 
-ID_BOOST([system thread test regex],[1.34])
+ID_BOOST([thread test regex],[1.34])
 if test -z "${BOOST_THREAD_LIB}"; then
 	AC_MSG_ERROR([Boost thread development libraries required])
 fi