diff --git a/lib/csharp/Makefile.am b/lib/csharp/Makefile.am
index 2e2d7fe..611405d 100644
--- a/lib/csharp/Makefile.am
+++ b/lib/csharp/Makefile.am
@@ -69,7 +69,11 @@
             src/TException.cs \
             src/TApplicationException.cs
 
+if MONO_MCS
+CSC=mcs
+else
 CSC=gmcs
+endif
 
 if NET_2_0
 MONO_DEFINES=/d:NET_2_0
diff --git a/lib/csharp/test/ThriftTest/Makefile.am b/lib/csharp/test/ThriftTest/Makefile.am
index fcde6fc..7125c90 100644
--- a/lib/csharp/test/ThriftTest/Makefile.am
+++ b/lib/csharp/test/ThriftTest/Makefile.am
@@ -18,7 +18,11 @@
 #
 
 THRIFT = $(top_builddir)/compiler/cpp/thrift
+if MONO_MCS
+CSC=mcs
+else
 CSC=gmcs
+endif
 
 stubs: $(top_srcdir)/test/ThriftTest.thrift
 	$(THRIFT) --gen csharp -o . $(top_srcdir)/test/ThriftTest.thrift