diff --git a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/configurators/apache/a2enmod.sh b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/configurators/apache/a2enmod.sh
index 60a62407a..4da9288a2 100755
--- a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/configurators/apache/a2enmod.sh
+++ b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/configurators/apache/a2enmod.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 # An extremely simplified version of `a2enmod` for enabling modules in the
-# httpd docker image. First argument is the ServerRoot and the second is the
-# module to be enabled.
+# httpd docker image. First argument is the Apache ServerRoot which should be
+# an absolute path. The second is the module to be enabled, such as `ssl`.
 
 confdir=$1
 module=$2