diff --git a/README.md b/README.md
index 8d2cee0..4581b2d 100644
--- a/README.md
+++ b/README.md
@@ -10,23 +10,10 @@ keys for signing emails.
 
 ## Requirements
 
-* Silverstripe framework ^4.5 (without file attachments)
+* Silverstripe framework ^4.9
 * OpenSSL ^1.1.1
 * Key pairs for encrypting and signing messages
 
-### Emailing file attachments
-
-There is a known issue with Swiftmailer 5.x wherein email clients are unable to
-decrypt encrypted emails which contain attachments.
-
-Any Silverstripe framework versions (>=4.0 <=4.8 at time of writing) which
-require Swiftmailer 5.x (usually dependency `swiftmailer/swiftmailer: ~5.4`) are
-susceptible to the issue.
-
-If email attachments are required please look at this Silverstripe framework
-[pull request for Swiftmailer v6
-support](https://github.com/silverstripe/silverstripe-framework/pull/10031).
-
 ## Installation
 
 ```
diff --git a/composer.json b/composer.json
index 6810cd1..656d0a2 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
     ],
     "license": "BSD-3-Clause",
     "require": {
-        "silverstripe/framework": "^4.5"
+        "silverstripe/framework": "^4.9"
     },
     "authors": [
         {