diff --git a/config.h.in b/config.h.in
index cce688618..3fd7953c9 100644
--- a/config.h.in
+++ b/config.h.in
@@ -42,6 +42,7 @@
 # undef HAVE_LIBREADLINE
 # undef HAVE_LIBZ
 # undef HAVE_LIBBZ2
+# undef HAVE_LROUND
 # undef HAVE_SYS_WAIT_H
 # undef WORDS_BIGENDIAN