diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73f6ac7..9af9957 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,22 @@
 # 1.7
 
+- Error model completely revised:
+  - All sum-types now follow the convention of having constructors suffixed with the type name. In particular the following transformations occurred:
+    - `QueryError` type got renamed to `SessionError`
+    - `QueryError` constructor got renamed to `QuerySessionError`
+    - New `PipelineSessionError` constructor got added to the `SessionError` type
+    - `ClientError` constructor got renamed to `ClientCommandError`
+    - `ResultError` constructor got renamed to `ResultCommandError`
+    - `ServerError` constructor got renamed to `ServerResultError`
+    - `UnexpectedResult` constructor got renamed to `UnexpectedResultError`
+    - `RowResult` constructor got renamed to `RowResultError`
+    - `RowError` type got renamed to `ColumnError`
+    - `EndOfInput` constructor got renamed to `EndOfInputColumnError`
+    - `UnexpectedNull` constructor got renamed to `UnexpectedNullColumnError`
+    - `ValueError` constructor got renamed to `UnexpectedNull`
+    - New `RowError` type got created
+    - `RowResult` constructor's column field go transferred into the new `RowError` type
+
 - Decidable instance on `Encoders.Params` removed. It was useless and limited the design.
 
 # 1.6.3.1