diff --git a/libc/private/bionic_tls.h b/libc/private/bionic_tls.h
index dd6b932..56a0ac2 100644
--- a/libc/private/bionic_tls.h
+++ b/libc/private/bionic_tls.h
@@ -114,7 +114,7 @@
 
 #if defined(__cplusplus)
 struct KernelArgumentBlock;
-extern void __libc_init_tls(KernelArgumentBlock& args);
+extern __LIBC_HIDDEN__ void __libc_init_tls(KernelArgumentBlock& args);
 #endif
 
 #endif /* _SYS_TLS_H */