diff --git a/lib/Makefile.am b/lib/Makefile.am
index 06cf11a..caf002f 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -2,6 +2,10 @@
   cpp \
   py
 
+if ENABLE_MONO
+SUBDIRS += csharp
+endif
+
 EXTRA_DIST = \
   cocoa \
   erl   \