Aside from section 5.7 (storable) and comments on 'alignPtr', the only mention of alignment in the FFI addendum is on mallocBytes/allocaBytes: "The block of memory is sufficiently aligned for any of the basic foreign types (see Section 3.2) that fits into a memory block of the allocated size" It would be beneficial if this wording was applied to all allocation routines - such as mallocForeignPtrBytes, mallocForeignPtrArray, etc. For the curious, this proposal was born from the real-world issue of pulling Word32's from a ByteString in an efficient but portable manner (binary is portable but inefficient, a straight forward unsafePerformIO/peek is efficient but need alignment). If no glaring issue comes up then I'll formalize / make a ticket, Thomas