diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 0bfbbf1..d2abea0 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -114,6 +114,7 @@
 
 __LIBC_HIDDEN__ int __init_thread(pthread_internal_t* thread);
 __LIBC_HIDDEN__ void __init_tls(pthread_internal_t* thread);
+__LIBC_HIDDEN__ void __init_thread_stack_guard(pthread_internal_t* thread);
 __LIBC_HIDDEN__ void __init_alternate_signal_stack(pthread_internal_t*);
 
 __LIBC_HIDDEN__ pthread_t           __pthread_internal_add(pthread_internal_t* thread);