diff --git a/libc/kernel/uapi/asm-arm/asm/signal.h b/libc/kernel/uapi/asm-arm/asm/signal.h
index 5f7e0c5..0424380 100644
--- a/libc/kernel/uapi/asm-arm/asm/signal.h
+++ b/libc/kernel/uapi/asm-arm/asm/signal.h
@@ -78,6 +78,6 @@
 typedef struct sigaltstack {
   void __user * ss_sp;
   int ss_flags;
-  size_t ss_size;
+  __kernel_size_t ss_size;
 } stack_t;
 #endif