diff --git a/include/ghc/filesystem.hpp b/include/ghc/filesystem.hpp
index ba4302c..51aac0f 100644
--- a/include/ghc/filesystem.hpp
+++ b/include/ghc/filesystem.hpp
@@ -3961,8 +3961,8 @@ GHC_INLINE void last_write_time(const path& p, file_time_type new_time, std::err
     struct ::timespec times[2];
     times[0].tv_sec = 0;
     times[0].tv_nsec = UTIME_OMIT;
-    times[1].tv_sec = std::chrono::duration_cast<std::chrono::seconds>(d).count();
-    times[1].tv_nsec = std::chrono::duration_cast<std::chrono::nanoseconds>(d).count() % 1000000000;
+    times[1].tv_sec = static_cast<decltype(times[1].tv_sec)>(std::chrono::duration_cast<std::chrono::seconds>(d).count());
+    times[1].tv_nsec = static_cast<decltype(times[1].tv_nsec)>(std::chrono::duration_cast<std::chrono::nanoseconds>(d).count() % 1000000000);
     if (::utimensat(AT_FDCWD, p.c_str(), times, AT_SYMLINK_NOFOLLOW) != 0) {
         ec = detail::make_system_error();
     }