diff --git a/libc/private/bionic_tls.h b/libc/private/bionic_tls.h
index 008fd2f..af19554 100644
--- a/libc/private/bionic_tls.h
+++ b/libc/private/bionic_tls.h
@@ -134,6 +134,9 @@
 /* return the stack base and size, used by our malloc debugger */
 extern void*  __get_stack_base(int  *p_stack_size);
 
+/* Initialize the TLS. */
+extern void __libc_init_tls(unsigned** elfdata);
+
 __END_DECLS
 
 #endif /* _SYS_TLS_H */