fuzz TEST document fuzzing regression testing
diff --git a/README.md b/README.md
index 011aad9..79a1e13 100644
--- a/README.md
+++ b/README.md
@@ -209,7 +209,11 @@
libyang includes several tests built with [cmocka](https://cmocka.org/). The tests
can be found in `tests` subdirectory and they are designed for checking library
-functionality after code changes.
+functionality after code changes. Additional regression tests done with
+a corpus of fuzzing inputs that previously caused crashes are done.
+Those are available in `tests/fuzz` and are built automatically with the
+cmocka unit tests.
+
The tests are by default built in the `Debug` build mode by running
```
diff --git a/tests/fuzz/README.md b/tests/fuzz/README.md
index e6641a1..6447da4 100644
--- a/tests/fuzz/README.md
+++ b/tests/fuzz/README.md
@@ -57,3 +57,6 @@
on a single core, with no starting inputs.
Multiple jobs running on separate cores should be used, with a starting input corpus.
The options are described in the official LibFuzzer documentation (https://llvm.org/docs/LibFuzzer.html).
+
+## Fuzzing corpus and regression testing
+The `tests/fuzz/corpus` directory contains subdirectories for every fuzz target. Those subdirectories contain a collection of previous inputs that were found by fuzzing and caused visible issues or crashes. Every input file is named after the issue or pull request where it was originally reported. When a new issue is discovered, the input causing the issue should be added to the appropriate directory.