diff --git a/libc/libc.x86_64.map b/libc/libc.x86_64.map
index 29c5235..2ba32bf 100644
--- a/libc/libc.x86_64.map
+++ b/libc/libc.x86_64.map
@@ -1286,6 +1286,7 @@
     sethostent;
     setnetent;
     setprotoent;
+    swab;
     syncfs;
 } LIBC_O;