diff --git a/.github/workflows/writing.yml b/.github/workflows/writing.yml
index 64e757b..56342a4 100644
--- a/.github/workflows/writing.yml
+++ b/.github/workflows/writing.yml
@@ -22,7 +22,7 @@ jobs:
 
     strategy:
         matrix:
-          os: [ubuntu-20.04, macos-10.15]
+          os: [ubuntu-22.04]
 
         fail-fast: false
 
diff --git a/writing/2021/pyboost11/code/Makefile b/writing/2021/pyboost11/code/Makefile
index 74ed854..cd7b4ad 100644
--- a/writing/2021/pyboost11/code/Makefile
+++ b/writing/2021/pyboost11/code/Makefile
@@ -35,4 +35,4 @@ test: modpyb$(pyextsuffix) modbpy$(pyextsuffix)
 
 .PHONY: clean
 clean:
-	rm -rf __pycache__ *.pyc *.pyo build *$(pyextsuffix)
+	rm -rf __pycache__ *.pyc *.pyo build *.so *.dylib