diff --git a/libc/include/sys/user.h b/libc/include/sys/user.h
index 432c7cb..0ea0285 100644
--- a/libc/include/sys/user.h
+++ b/libc/include/sys/user.h
@@ -34,8 +34,10 @@
 
 __BEGIN_DECLS
 
+#if !defined(__BIONIC_NO_PAGE_SIZE_MACRO)
 #define PAGE_SIZE 4096
 #define PAGE_MASK (~(PAGE_SIZE - 1))
+#endif
 
 #if defined(__i386__)