diff --git a/js/src/xpconnect/idl/.cvsignore b/js/src/xpconnect/idl/.cvsignore
new file mode 100644
index 000000000000..f3c7a7c5da68
--- /dev/null
+++ b/js/src/xpconnect/idl/.cvsignore
@@ -0,0 +1 @@
+Makefile