diff --git a/heed/src/lib.rs b/heed/src/lib.rs
index 83a5d15d..cd35e34c 100644
--- a/heed/src/lib.rs
+++ b/heed/src/lib.rs
@@ -89,7 +89,7 @@ pub use self::iterator::{
     RwRevIter, RwRevPrefix, RwRevRange,
 };
 pub use self::mdb::error::Error as MdbError;
-use self::mdb::ffi::{from_val, into_val};
+pub use self::mdb::ffi::{from_val, into_val, MDB_val};
 pub use self::mdb::flags::{DatabaseFlags, EnvFlags, PutFlags};
 pub use self::reserved_space::ReservedSpace;
 pub use self::traits::{BoxedError, BytesDecode, BytesEncode, Comparator, LexicographicComparator};
diff --git a/heed/src/mdb/lmdb_ffi.rs b/heed/src/mdb/lmdb_ffi.rs
index ce99b460..09729b14 100644
--- a/heed/src/mdb/lmdb_ffi.rs
+++ b/heed/src/mdb/lmdb_ffi.rs
@@ -34,10 +34,12 @@ pub fn reserve_size_val(size: usize) -> ffi::MDB_val {
     ffi::MDB_val { mv_size: size, mv_data: ptr::null_mut() }
 }
 
+#[allow(missing_docs)]
 pub unsafe fn into_val(value: &[u8]) -> ffi::MDB_val {
     ffi::MDB_val { mv_data: value.as_ptr() as *mut libc::c_void, mv_size: value.len() }
 }
 
+#[allow(missing_docs)]
 pub unsafe fn from_val<'a>(value: ffi::MDB_val) -> &'a [u8] {
     std::slice::from_raw_parts(value.mv_data as *const u8, value.mv_size)
 }