diff --git a/Understanding-and-debugging-Nimbus-EVM-JSON-tests.md b/Understanding-and-debugging-Nimbus-EVM-JSON-tests.md
index fc7949d..923d755 100644
--- a/Understanding-and-debugging-Nimbus-EVM-JSON-tests.md
+++ b/Understanding-and-debugging-Nimbus-EVM-JSON-tests.md
@@ -15,13 +15,19 @@ Run Ethereum [JSON-based general state tests](https://github.com/ethereum/tests/
 mkdir -p build
 nim c -r -o:build/test_generalstate_json tests/test_generalstate_json.nim
 ```
+You might want to run the tests with `-d:release` flag as some tests might end up with a stack overflow in `debug` mode.
 
 Build and run an individual test (with tracing enabled):
 ```
-nim c -r -d:chronicles_log_level=TRACE -o:build/test_generalstate_json tests/test_generalstate_json.nim tests/fixtures/GeneralStateTests/stAttackTest/ContractCreationSpam.json
+nim c -r -d:chronicles_log_level=TRACE -o:build/test_generalstate_json tests/test_generalstate_json.nim stAttackTest/ContractCreationSpam.json
 ```
 (this particular test needs to be commented out of "tests/test_generalstate_failing.nim" before running it)
 
+Individual tests are default only tested on Frontier fork. You can change the fork with `--fork:`, e.g.:
+```
+nim c -d:release -r -o:build/test_generalstate_json tests/test_generalstate_json.nim stCallCreateCallCodeTest/Call1024BalanceTooLow.json --fork:Byzantium
+```
+
 ## VMTests
 
 ### JSON structure