diff --git a/test/fuzz/readme.md b/test/fuzz/readme.md
index 01d0556e..969b3ee1 100644
--- a/test/fuzz/readme.md
+++ b/test/fuzz/readme.md
@@ -45,6 +45,13 @@ TARGET=createMessageBinary npm run fuzz-coverage
 
 The coverage reports can be found in `test/fuzz/coverage`.
 
+_Note:_ The output will tell you that using `--sync` might be useful:
+> Exclusively observed synchronous return values from fuzzed function. Fuzzing in synchronous mode seems beneficial!
+To enable it, append a `--sync` to your Jazzer.js invocation.
+
+But, [be careful](https://github.com/CodeIntelligenceTesting/jazzer.js/blob/main/docs/fuzz-targets.md#synchronous-execution).
+It **may only be used for entirely synchronous code** and it is not fully compatible with callbacks, that are used in the tests.
+
 
 ## The fuzz target module
 All functions that need to be fuzz-tested are here, at the `test/fuzz/` directory.