diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index eafbbd7..0f1e325 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1391,6 +1391,7 @@
     sethostent;
     setnetent;
     setprotoent;
+    swab;
     syncfs;
 } LIBC_O;