diff --git a/docs/bugs.json b/docs/bugs.json
index f6ce8f6fe..0b72c05c7 100644
--- a/docs/bugs.json
+++ b/docs/bugs.json
@@ -1,4 +1,15 @@
 [
+    {
+        "uid": "SOL-2021-4",
+        "name": "UserDefinedValueTypesBug",
+        "summary": "User defined value types with underlying type shorter than 32 bytes used incorrect storage layout and wasted storage",
+        "description": "The compiler did not correctly compute the storage layout of user defined value types based on types that are shorter than 32 bytes. It would always use a full storage slot for these types, even if the underlying type was shorter. This was wasteful and might have problems with tooling or contract upgrades.",
+        "link": "https://blog.soliditylang.org/2021/09/29/user-defined-value-types-bug/",
+        "introduced": "0.8.8",
+        "fixed": "0.8.9",
+        "severity": "very low"
+
+    },
     {
         "uid": "SOL-2021-3",
         "name": "SignedImmutables",
diff --git a/docs/bugs_by_version.json b/docs/bugs_by_version.json
index c6af59bda..bfba53e45 100644
--- a/docs/bugs_by_version.json
+++ b/docs/bugs_by_version.json
@@ -1585,6 +1585,7 @@
     },
     "0.8.8": {
         "bugs": [
+            "UserDefinedValueTypesBug",
             "SignedImmutables"
         ],
         "released": "2021-09-27"