diff --git a/doc/developer-notes.md b/doc/developer-notes.md
index a4139ee2b..a5722ce3b 100644
--- a/doc/developer-notes.md
+++ b/doc/developer-notes.md
@@ -338,6 +338,10 @@ Current subtrees include:
   - **Note**: Follow the instructions in [Upgrading LevelDB](#upgrading-leveldb) when
     merging upstream changes to the LevelDB subtree.
 
+- src/crc32c
+  - Used by leveldb for hardware acceleration of CRC32C checksums for data integrity.
+  - Upstream at https://github.com/google/crc32c ; Maintained by Google.
+
 - src/secp256k1
   - Upstream at https://github.com/bitcoin-core/secp256k1/ ; actively maintained by Core contributors.