diff --git a/README.md b/README.md
index ff92bbd..fb93008 100644
--- a/README.md
+++ b/README.md
@@ -23,8 +23,16 @@
 
 ### Building
 
-Building with default settings requires CMake for the configuration and make for
-building. This will produce an elf file which can be run on the FVP.
+Building with default settings requires CMake for the configuration, make for
+building and Python 3 for helper scripts.
+
+Before the first time building, install the required Python modules.
+
+```
+$ pip install -r requirements.txt
+```
+
+The following commands will produce an elf file which can be run on the FVP.
 
 ```
 $ cmake -B build/corstone-300 targets/corstone-300
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..5e03a5c
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,2 @@
+numpy
+pyelftools