diff --git a/Makefile b/Makefile
index 0faf653..2e51447 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 # ==================
 
 # Default variables
-PYTHON_DIRS = sia tools test
+PYTHON_DIRS = lib sia test tools
 RUST_DIRS = lib/xml_schema_validator
 WEB_DIRS = web