diff --git a/libm/libm.map.txt b/libm/libm.map.txt
index 1fb16b7..1f9a3f9 100644
--- a/libm/libm.map.txt
+++ b/libm/libm.map.txt
@@ -271,7 +271,7 @@
     *;
 };
 
-LIBC_O {
+LIBC_O { # introduced=O
   global:
     cacoshl;
     cacosl;