Index: lib/sanitizer_common/sanitizer_linux.cc
===================================================================
--- lib/sanitizer_common/sanitizer_linux.cc
+++ lib/sanitizer_common/sanitizer_linux.cc
@@ -104,7 +104,7 @@
 
 // --------------- sanitizer_libc.h
 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
-                   u64 offset) {
+                   uptr offset) {
 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
   return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
                           offset);
Index: lib/sanitizer_common/sanitizer_posix.h
===================================================================
--- lib/sanitizer_common/sanitizer_posix.h
+++ lib/sanitizer_common/sanitizer_posix.h
@@ -35,7 +35,7 @@
 
 // Memory
 uptr internal_mmap(void *addr, uptr length, int prot, int flags,
-                   int fd, u64 offset);
+                   int fd, uptr offset);
 uptr internal_munmap(void *addr, uptr length);
 int internal_mprotect(void *addr, uptr length, int prot);