diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 7986ada..bfa4e8c 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -44,7 +44,7 @@
 #include "private/ScopedPthreadMutexLocker.h"
 
 // x86 uses segment descriptors rather than a direct pointer to TLS.
-#if __i386__
+#if defined(__i386__)
 #include <asm/ldt.h>
 void __init_user_desc(struct user_desc*, bool, void*);
 #endif
diff --git a/libc/include/sys/user.h b/libc/include/sys/user.h
index 5601b02..f9ad956 100644
--- a/libc/include/sys/user.h
+++ b/libc/include/sys/user.h
@@ -38,7 +38,7 @@
 #define PAGE_SIZE 4096
 #define PAGE_MASK (~(PAGE_SIZE - 1))
 
-#if __i386__
+#if defined(__i386__)
 
 struct user_fpregs_struct {
   long cwd;