diff --git a/examples/calc++/.cvsignore b/examples/calc++/.cvsignore
index bf4fe16f..cacb7664 100644
--- a/examples/calc++/.cvsignore
+++ b/examples/calc++/.cvsignore
@@ -4,6 +4,7 @@
 *.output
 *.stamp
 *.tmp
+*.yy
 .deps
 Makefile
 Makefile.in