diff --git a/syndicate/mc/preserve.md b/syndicate/mc/preserve.md
index 6fa70bf..97892f4 100644
--- a/syndicate/mc/preserve.md
+++ b/syndicate/mc/preserve.md
@@ -897,7 +897,7 @@ or `Record`s.
  - `Boolean` ↔ `True` and `False`
  - `Float` ↔ a `Float` wrapper-class for a double-precision value
  - `Double` ↔ float
- - `SignedInteger` ↔ int
+ - `SignedInteger` ↔ int and long
  - `String` ↔ `unicode`
  - `ByteString` ↔ `bytes`
  - `Symbol` ↔ a simple data class wrapping a `unicode`