diff --git a/libc/kernel/uapi/asm-generic/signal.h b/libc/kernel/uapi/asm-generic/signal.h
index 874fece..5cb1dce 100644
--- a/libc/kernel/uapi/asm-generic/signal.h
+++ b/libc/kernel/uapi/asm-generic/signal.h
@@ -84,7 +84,7 @@
 typedef struct sigaltstack {
   void __user * ss_sp;
   int ss_flags;
-  size_t ss_size;
+  __kernel_size_t ss_size;
 } stack_t;
 #endif
 #endif