diff --git a/cleanup.sh b/cleanup.sh
index 4760f43..fe0d6ed 100755
--- a/cleanup.sh
+++ b/cleanup.sh
@@ -34,4 +34,5 @@
 lib/Makefile.in \
 lib/cpp/Makefile.in \
 lib/py/Makefile.in \
+lib/csharp/Makefile.in \
 test/Makefile.in