diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d12256df..e1fa8db60 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [4.4.2] - 2021-01-08
+## [4.5.0-pre.1] - 2021-01-08
+
+### Bug Fixes
 
 - Fixed the insertion of new points on a Poly Shape being unreliable.
 - Fixed rect selection not working with Universal Render Pipeline.
@@ -13,6 +15,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - [case: 1294866] Fix annotation warning on InitializeOnLoad call.
 - [case: 1304561] Fix `Shape Preview` not rendering with the blue preview tint.
 
+### Changes
+
+- Drop support for Unity 2018.3. This was necessary for optional assembly references.
+
 ## [4.4.1] - 2020-11-10
 
 - [case: 1286720] Fixed `Bezier Shape` and `Poly Shape` component preventing build when `Script Stripping` was enabled.
diff --git a/package.json b/package.json
index cf4e403d5..1287c3a95 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "com.unity.probuilder",
   "displayName": "ProBuilder",
-  "version": "4.4.2",
+  "version": "4.5.0-pre.1",
   "unity": "2018.4",
   "description": "Build, edit, and texture custom geometry in Unity. Use ProBuilder for in-scene level design, prototyping, collision meshes, all with on-the-fly play-testing.\n\nAdvanced features include UV editing, vertex colors, parametric shapes, and texture blending. With ProBuilder's model export feature it's easy to tweak your levels in any external 3D modelling suite.",
   "keywords": [