diff --git a/doc/doxygen/src/creating-modules.md b/doc/doxygen/src/creating-modules.md
index 63d2c840d6f9b302035dfc9420e9e048deb6e7ac..82d54be0008be6c480b67c7842b1a42a32a89f25 100644
--- a/doc/doxygen/src/creating-modules.md
+++ b/doc/doxygen/src/creating-modules.md
@@ -34,6 +34,20 @@ current configuration or not.
 Modules can be used by adding their name to the `USEMODULE` macro of your
 application's Makefile.
 
+### Pitfalls ###
+
+The `MODULE` name should be unique or build breaks as modules overwrite the
+same output file.
+
+This problem happened in the past for:
+
+ * Packages root directory (libfixmath/u8g2)
+ * boards/cpu/periph and their common boards/cpu/periph
+
+Note: even if all boards and cpus implement the `board` and `cpu` modules, only
+      one is used in an application so there is no conflict.
+
+
 Module dependencies
 ===================
 Your module may depend on other modules to minimize code duplication. These