diff --git a/SECURITY.md b/SECURITY.md
index 7a79d9f91..9a08c4e25 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -13,9 +13,9 @@ A "vulnerability in Mastodon" is a vulnerability in the code distributed through
 
 ## Supported Versions
 
-| Version | Supported |
-| ------- | --------- |
-| 4.1.x   | Yes       |
-| 4.0.x   | Yes       |
-| 3.5.x   | Yes       |
-| < 3.5   | No        |
+| Version | Supported        |
+| ------- | ---------------- |
+| 4.1.x   | Yes              |
+| 4.0.x   | Until 2023-10-31 |
+| 3.5.x   | Until 2023-12-31 |
+| < 3.5   | No               |