diff --git a/libc/bionic/pthread_exit.cpp b/libc/bionic/pthread_exit.cpp
index 6b68bb7..afda089 100644
--- a/libc/bionic/pthread_exit.cpp
+++ b/libc/bionic/pthread_exit.cpp
@@ -81,7 +81,8 @@
 
   if (thread->alternate_signal_stack != NULL) {
     // Tell the kernel to stop using the alternate signal stack.
-    stack_t ss = {};
+    stack_t ss;
+    memset(&ss, 0, sizeof(ss));
     ss.ss_flags = SS_DISABLE;
     sigaltstack(&ss, NULL);