diff --git a/tests/README.md b/tests/README.md
index 068ef8301..7fb2e3b8a 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -8,9 +8,15 @@ initrd images for all supported distributions and then tests them to ensure a
 Kata Container can be created with each.
 
 Before the build phase, the test script installs the Docker container manager
-and all the Kata components required to run test containers. This step can be
-skipped by setting the environment variable `KATA_DEV_MODE` to a non-empty
-value.
+and all the Kata components required to run test containers. Individual tests
+will also alter host `kata-runtime` and `docker` service configuration as needed.
+
+All host config editing can be skipped by setting the environment variable
+`KATA_DEV_MODE` to a non-empty value. In this mode, image/initrd targets
+will be built but not runtime tested; If your host is configured to have
+`kata-runtime` set as the default docker runtime, you will need to switch
+to a runtime like `runc`/`crun` so the `docker build` test commands work
+correctly.
 
 ```
 $ ./test_images.sh