diff --git a/win32.c b/win32.c
index 0f789dbfaf..9f1cb6c15f 100644
--- a/win32.c
+++ b/win32.c
@@ -720,7 +720,7 @@ void FiosGetDrives(void)
 bool FiosIsValidFile(const char *path, const struct dirent *ent, struct stat *sb)
 {
 	// hectonanoseconds between Windows and POSIX epoch
-	static const int64 posix_epoch_hns = 0x019DB1DED53E8000;
+	static const int64 posix_epoch_hns = 0x019DB1DED53E8000LL;
 	const WIN32_FIND_DATA *fd = &ent->dir->fd;
 	if (fd->dwFileAttributes & (FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_SYSTEM)) return false;