diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd08e48e..d4ba74c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,22 @@
 # Changelog
 
+## [v4.0.0] - 2020-09-02
+
+### Added:
+
+- **[cli], [lib]** Support "alternate" certificate links for selecting different signing Chains
+
+### Changed:
+
+- **[cli]** Replaces `ec384` by `ec256` as default key-type
+- **[lib]** Changes `ObtainForCSR` method signature
+
+### Removed:
+
+- **[dnsprovider]** Replaces FastDNS by EdgeDNS
+- **[dnsprovider]** Removes old Linode provider
+- **[lib]** Removes `AddPreCheck` function
+
 ## [v3.9.0] - 2020-09-01
 
 ### Added:
diff --git a/acme/api/internal/sender/useragent.go b/acme/api/internal/sender/useragent.go
index 19463e50..254ea545 100644
--- a/acme/api/internal/sender/useragent.go
+++ b/acme/api/internal/sender/useragent.go
@@ -5,10 +5,10 @@ package sender
 
 const (
 	// ourUserAgent is the User-Agent of this underlying library package.
-	ourUserAgent = "xenolf-acme/3.9.0"
+	ourUserAgent = "xenolf-acme/4.0.0"
 
 	// ourUserAgentComment is part of the UA comment linked to the version status of this underlying library package.
 	// values: detach|release
 	// NOTE: Update this with each tagged release.
-	ourUserAgentComment = "detach"
+	ourUserAgentComment = "release"
 )