diff --git a/CHANGELOG.md b/CHANGELOG.md
index bee5de0d7e..00f9418771 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,8 +26,12 @@ and this project adheres to
   `ConversionOverflowError` and `DivideByZeroError`. ([#1896])
 - cosmwasm-std: Add `SubMsg:reply_never` constructor ([#1929])
 - cosmwasm-std: Add optional memo field to `IbcMsg::Transfer`. ([#1878])
+- cosmwasm-std: Make inner values of `CanonicalAddr` and `Binary` private and
+  add constructor for `Binary`. ([#1876])
+- cosmwasm-vm: Make inner value of `Size` private and add constructor. ([#1876])
 
 [#1874]: https://github.com/CosmWasm/cosmwasm/pull/1874
+[#1876]: https://github.com/CosmWasm/cosmwasm/pull/1876
 [#1878]: https://github.com/CosmWasm/cosmwasm/pull/1878
 [#1879]: https://github.com/CosmWasm/cosmwasm/pull/1879
 [#1890]: https://github.com/CosmWasm/cosmwasm/pull/1890
diff --git a/MIGRATING.md b/MIGRATING.md
index 559581566c..f367462f30 100644
--- a/MIGRATING.md
+++ b/MIGRATING.md
@@ -69,6 +69,22 @@ major releases of `cosmwasm`. Note that you can also view the
   +Coin::new(1234u128, "uatom")
   ```
 
+- When creating a `Binary` or `Size` instance from an inner value, you now have
+  to explicitly call `new`:
+
+  ```diff
+  -Binary(vec![1u8])
+  +Binary::new(vec![1u8])
+  ```
+
+- When accessing the inner value of a `CanonicalAddr` or `Binary`, use
+  `as_slice` instead:
+
+  ```diff
+  -&canonical_addr.0
+  +canonical_addr.as_slice()
+  ```
+
 ## 1.4.x -> 1.5.0
 
 - Update `cosmwasm-*` dependencies in Cargo.toml (skip the ones you don't use):