Use off_t instead of __off_t __off_t is an internal C library type, which shouldn't be used by applications. It is not defined by the musl C library, so use the public off_t type instead. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Index: b/ftpfs.c =================================================================== --- a/ftpfs.c +++ b/ftpfs.c @@ -687,7 +687,7 @@ return ftpfs_getattr(path, &sbuf); } -static __off_t test_size(const char* path) +static off_t test_size(const char* path) { struct stat sbuf; int err = ftpfs_getattr(path, &sbuf); @@ -950,7 +950,7 @@ /* fix openoffice problem, truncating exactly to file length */ - __off_t size = (long long int)test_size(path); + off_t size = (long long int)test_size(path); DEBUG(1, "ftpfs_truncate: %s check filesize=%lld\n", path, (long long int)size); if (offset == size) @@ -978,7 +978,7 @@ } /* fix openoffice problem, truncating exactly to file length */ - __off_t size = test_size(path); + off_t size = test_size(path); DEBUG(1, "ftpfs_ftruncate: %s check filesize=%lld\n", path, (long long int)size); if (offset == size)