diff --git a/saison-2/cours/.gitignore b/saison-2/cours/.gitignore
index a136337..89ab085 100644
--- a/saison-2/cours/.gitignore
+++ b/saison-2/cours/.gitignore
@@ -1 +1,2 @@
 *.pdf
+build/
diff --git a/saison-2/cours/Makefile b/saison-2/cours/Makefile
deleted file mode 100644
index 36bd93d..0000000
--- a/saison-2/cours/Makefile
+++ /dev/null
@@ -1,4 +0,0 @@
-all: ./e2l-python-classes-01.pdf
-
-%.pdf: %.md
-	pandoc --pdf-engine=xelatex $< -o $@
diff --git a/saison-2/cours/build.in.ninja b/saison-2/cours/build.in.ninja
new file mode 100644
index 0000000..402d8b9
--- /dev/null
+++ b/saison-2/cours/build.in.ninja
@@ -0,0 +1,2 @@
+rule pandoc
+  command = pandoc --pdf-engine=xelatex $in -o $out
diff --git a/saison-2/cours/build.py b/saison-2/cours/build.py
new file mode 100644
index 0000000..4c5d395
--- /dev/null
+++ b/saison-2/cours/build.py
@@ -0,0 +1,21 @@
+from path import Path
+import sys
+import subprocess
+
+
+def main():
+    template = Path("build.in.ninja").text()
+    to_write = template
+    for md_file in Path(".").files("*.md"):
+        to_write += f"build  ../{md_file.with_suffix('.pdf')}: pandoc ../{md_file}\n"
+    build_path = Path("build")
+    build_path.mkdir_p()
+    out = build_path / "build.ninja"
+    out.write_text(to_write)
+    process = subprocess.run(["ninja", "-C", build_path])
+    if process.returncode != 0:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()