diff --git a/libc/libc.x86.brillo.map b/libc/libc.x86.brillo.map
index d483d3e..f14861d 100644
--- a/libc/libc.x86.brillo.map
+++ b/libc/libc.x86.brillo.map
@@ -1261,6 +1261,7 @@
     getpwent;
     getsubopt;
     hasmntopt;
+    mblen;
     pthread_getname_np;
     quotactl;
     setdomainname;