diff --git a/Changes b/Changes
index 2350f6e30e..9f4c7588f4 100644
--- a/Changes
+++ b/Changes
@@ -1,7 +1,12 @@
+# 9.0.0-a4
+
 #### IECore
 
 - Bug fix in StreamIndexedIO that was causing sporadic crashes when loading SceneCaches during procedural expansion.
-
+- Fixed some minor bounding box bugs in IECore.SceneCache
+- Child bounds can now dilate bounds explicitly specified using IECore.SceneCache.writeBound()
+- IECore.LinkedScene now supports extra children at link locations
+- Fixed TransformOp double transform bug
 
 # 9.0.0-a3
 
diff --git a/SConstruct b/SConstruct
index c17edb14a8..85ca436b84 100644
--- a/SConstruct
+++ b/SConstruct
@@ -53,7 +53,7 @@ SConsignFile()
 ieCoreMajorVersion=9
 ieCoreMinorVersion=0
 ieCorePatchVersion=0
-ieCoreVersionSuffix="a3"	# used for alpha/beta releases. Example: "a1", "b2", etc.
+ieCoreVersionSuffix="a4"	# used for alpha/beta releases. Example: "a1", "b2", etc.
 
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 # Command line options