diff --git a/README.md b/README.md
index 79b3254..6b26f26 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,5 @@ docker run -it -v zephyr:/workdir --rm zephyr-config
 2. Create a new project by selecting the second option
 3. Open the `$HOME/zephyrproject/app` directory in your IDE. The source code is located in the `src` subdirectory.
 4. Build and flash the project using the options 4 and 5.
+
+If you want to compile zepyhr for another plattform you have to clear the build directory first.