diff --git a/testing/.gitignore b/testing/.gitignore
new file mode 100644
index 000000000..d4748c007
--- /dev/null
+++ b/testing/.gitignore
@@ -0,0 +1,3 @@
+# in case anyone wants to keep ert in the testing directory, e.g., for
+# old versions of Emacs
+ert