diff --git a/image_builder/README.md b/image_builder/README.md
index e2af3a87..d4b0242e 100644
--- a/image_builder/README.md
+++ b/image_builder/README.md
@@ -79,3 +79,11 @@ sudo systemctl start jenkins
 ## Requirements
 
 * Jenkins (BlueOcean plugin, optional)
+
+## Troubleshooting
+
+If JDK not installed:
+
+```bash
+sudo apt-get install default-jdk
+```