diff --git a/configure.ac b/configure.ac
index 48f93b5..ad926b0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -474,6 +474,7 @@
   lib/py/Makefile
   lib/rb/Makefile
   test/Makefile
+  test/cpp/Makefile
   test/hs/Makefile
   test/py/Makefile
   test/py.twisted/Makefile