diff --git a/config.mak.in b/config.mak.in
index 10698c8..b2ba710 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -74,3 +74,4 @@
 NO_PTHREADS=@NO_PTHREADS@
 PTHREAD_CFLAGS=@PTHREAD_CFLAGS@
 PTHREAD_LIBS=@PTHREAD_LIBS@
+CHARSET_LIB=@CHARSET_LIB@