diff --git a/README.md b/README.md
index 23a6e85..f251ec8 100644
--- a/README.md
+++ b/README.md
@@ -10,3 +10,9 @@ See Sourcecode for Examples
 
 * Website: https://github.com/stefankoegl/python-json-patch
 * Repository: https://github.com/stefankoegl/python-json-patch.git
+
+Running external tests
+----------------------
+To run external tests (such as those from https://github.com/json-patch/json-patch-tests) use ext_test.py 
+
+    ./ext_tests.py ../json-patch-tests/tests.json