diff --git a/letsencrypt-auto-source/pieces/fetch.py b/letsencrypt-auto-source/pieces/fetch.py
index d11f8da61..365a5a36a 100644
--- a/letsencrypt-auto-source/pieces/fetch.py
+++ b/letsencrypt-auto-source/pieces/fetch.py
@@ -2,7 +2,7 @@
 
     # Print latest released version of LE to stdout:
     python fetch.py --latest-version
-    
+
     # Download letsencrypt-auto script from git tag v1.2.3 into the folder I'm
     # in, and make sure its signature verifies:
     python fetch.py --le-auto-script v1.2.3
diff --git a/tests/modification-check.sh b/tests/modification-check.sh
new file mode 100755
index 000000000..53a5efa93
--- /dev/null
+++ b/tests/modification-check.sh
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+temp_dir=`mktemp -d`
+
+# Script should be run from Certbot's root directory
+cp letsencrypt-auto ${temp_dir}/letsencrypt-to-be-checked
+cp certbot-auto ${temp_dir}/certbot-to-be-checked
+
+cp letsencrypt-auto-source/pieces/fetch.py ${temp_dir}/fetch.py
+cd ${temp_dir}
+
+LATEST_VERSION=`python fetch.py --latest-version`
+python fetch.py --le-auto-script v${LATEST_VERSION}
+
+cmp -s letsencrypt-auto letsencrypt-to-be-checked
+
+if [ $? != 0 ]; then
+	echo "Root letsencrypt-auto has changed."
+	rm -rf temp_dir
+	exit 1
+else
+	echo "Root letsencrypt-auto is unchanged."
+fi
+
+cmp -s letsencrypt-auto certbot-to-be-checked
+
+if [ $? != 0 ]; then
+	echo "Root certbot-auto has changed."
+	rm -rf temp_dir
+	exit 1
+else
+	echo "Root certbot-auto is unchanged."
+fi
+
+rm -rf temp_dir
diff --git a/tox.ini b/tox.ini
index 1a2eed369..19297d38d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -95,6 +95,7 @@ commands =
 # At the moment, this tests under Python 2.7 only, as only that version is
 # readily available on the Trusty Docker image.
 commands =
+    {toxinidir}/tests/modification-check.sh
     docker build -t lea letsencrypt-auto-source
     docker run --rm -t -i lea
 whitelist_externals =