### B.5 Using 32-Bit Dictionaries on a 64-Bit System

Due to an oversight, Aspell compiled dictionaries not only depend on the endian order, they also depend on the the size of the `size_t` type, which is generally different on 32 and 64-bit systems. The `size_t` type is used in the hash function of the compiled dictionaries. To force the hash function to use a 32-bit integer instead, use the `--enable-32-bit-hash-fun` configure option. This option will allow you to use dictionaries compiled on a 32-bit machine on a 64-bit one as long as the endian order is the same. Of course, dictionaries compiled on a 64-bit machine without this option enabled will no longer be usable. If Aspell detects that an incompatible hash function is used, it will fail with:

> Error: The file “some-file” is not in the proper format. Incompatible hash function.