diff --git a/doc/decompressor_errata.md b/doc/decompressor_errata.md
index b162e7fd6..6c99cb01f 100644
--- a/doc/decompressor_errata.md
+++ b/doc/decompressor_errata.md
@@ -6,12 +6,29 @@ Each entry will contain:
 1. The last affected decompressor versions.
 2. The decompressor components affected.
 2. Whether the compressed frame could ever be produced by the reference compressor.
-3. An example frame.
+3. An example frame when it can be short enough to be displayed as hexadecimal
 4. A description of the bug.
 
 The document is in reverse chronological order, with the bugs that affect the most recent zstd decompressor versions listed first.
 
 
+Compressed block with a size of exactly 128 KB
+------------------------------------------------
+
+**Last affected version**: v1.5.2
+
+**Affected decompressor component(s)**: Library & CLI
+
+**Produced by the reference compressor**: No
+
+The zstd decoder incorrectly rejected blocks of type `Compressed_Block` when their size was exactly 128 KB.
+
+This type of block was never generated by the reference compressor.
+
+These blocks used to be disallowed by the spec up until spec version 0.3.2 when the restriction was lifted by [PR#1689](https://github.com/facebook/zstd/pull/1689).
+
+> A Compressed_Block has the extra restriction that Block_Size is always strictly less than the decompressed size. If this condition cannot be respected, the block must be sent uncompressed instead (Raw_Block).
+
 Compressed block with 0 literals and 0 sequences
 ------------------------------------------------