diff --git a/libc/include/bits/lockf.h b/libc/include/bits/lockf.h
index 58ab03113..ec6e53cfe 100644
--- a/libc/include/bits/lockf.h
+++ b/libc/include/bits/lockf.h
@@ -60,7 +60,7 @@ int lockf(int __fd, int __cmd, off_t __length) __RENAME_IF_FILE_OFFSET64(lockf64
 
 /**
  * Like lockf() but allows using a 64-bit length
- * even from a 32-bit process without `__FILE_OFFSET_BITS=64`.
+ * even from a 32-bit process without `_FILE_OFFSET_BITS=64`.
  */
 int lockf64(int __fd, int __cmd, off64_t __length) __INTRODUCED_IN(24);
 
diff --git a/libc/include/sys/sendfile.h b/libc/include/sys/sendfile.h
index 4b00d5dc8..f953473fd 100644
--- a/libc/include/sys/sendfile.h
+++ b/libc/include/sys/sendfile.h
@@ -55,7 +55,7 @@ ssize_t sendfile(int __out_fd, int __in_fd, off_t* _Nullable __offset, size_t __
 
 /**
  * Like sendfile() but allows using a 64-bit offset
- * even from a 32-bit process without `__FILE_OFFSET_BITS=64`.
+ * even from a 32-bit process without `_FILE_OFFSET_BITS=64`.
  */
 ssize_t sendfile64(int __out_fd, int __in_fd, off64_t* _Nullable __offset, size_t __count) __INTRODUCED_IN(21);