diff --git a/specs/networking/rpc-interface.md b/specs/networking/rpc-interface.md
index e59f6a6b1..e087abe96 100644
--- a/specs/networking/rpc-interface.md
+++ b/specs/networking/rpc-interface.md
@@ -165,7 +165,7 @@ Client MAY send `goodbye` messages upon disconnection. The reason field MUST be
 ```
 # BlockRootSlot
 (
-    block_root: HashTreeRoot
+    block_root: bytes32
     slot: uint64
 )