diff --git a/libc/private/kernel_sigset_t.h b/libc/private/kernel_sigset_t.h
index 733a842..b2d6386 100644
--- a/libc/private/kernel_sigset_t.h
+++ b/libc/private/kernel_sigset_t.h
@@ -32,7 +32,7 @@
   }
 
   void clear() {
-    memset(this, 0, sizeof(*this));
+    __builtin_memset(this, 0, sizeof(*this));
   }
 
   void set(const sigset_t* value) {