Fix distcheck
diff --git a/configure.ac b/configure.ac
index 41d36f2..6cebf9b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -143,5 +143,6 @@
 		 shared/Makefile
 		 src/Makefile
 		 clients/Makefile
-		 data/Makefile])
+		 data/Makefile
+		 protocol/Makefile])
 AC_OUTPUT