// WARNING: OFF_T may be different from OS type off_t, depending on the value of
// _FILE_OFFSET_BITS. This definition of OFF_T matches the ABI of system calls
// like pread and mmap, as opposed to pread64 and mmap64.
-// Mac is special.
-#ifdef __APPLE__
+// Mac and Linux/x86-64 are special.
+#if defined(__APPLE__) || (defined(__linux__) && defined(__x86_64__))
typedef __sanitizer::u64 OFF_T;
#else
typedef __sanitizer::uptr OFF_T;