diff --git a/iconv/gconv_conf.c b/iconv/gconv_conf.c
index 83d962129f..475338f7ca 100644
--- a/iconv/gconv_conf.c
+++ b/iconv/gconv_conf.c
@@ -29,6 +29,7 @@
 #include <unistd.h>
 #include <sys/param.h>
 
+#include <bits/libc-lock.h>
 #include <gconv_int.h>