diff --git a/specs/simple-serialize.md b/specs/simple-serialize.md
index 82d472ea4..d7ac4e992 100644
--- a/specs/simple-serialize.md
+++ b/specs/simple-serialize.md
@@ -392,7 +392,7 @@ return typ(**values), item_index
 
 The below `SSZTreeHash` algorithm is defined recursively in the case of lists and containers, and it outputs a value equal to or less than 32 bytes in size. For the final output only (ie. not intermediate outputs), if the output is less than 32 bytes, right-zero-pad it to 32 bytes. The goal is collision resistance *within* each type, not between types.
 
-We define `hash(x)` as `BLAKE2b-512(x)[0:32]`.
+Refer to Appendix A of Phase 0 of the [Eth2.0 specs](https://github.com/ethereum/eth2.0-specs) for a definition of the hash function used below, `hash(x)`.
 
 #### `uint8`..`uint256`, `bool`, `address`, `hash1`..`hash32`