diff --git a/plugins/disqus.lisp b/plugins/disqus.lisp
index ca89f89..36f9545 100644
--- a/plugins/disqus.lisp
+++ b/plugins/disqus.lisp
@@ -3,9 +3,6 @@
 
 (in-package :coleslaw-disqus)
 
-;; Should be added to plugins like so:
-; :plugins (mathjax (disqus :shortname "mysite-disqus-shortname"))
-
 (defvar *disqus-header*
   "<div id=\"disqus_thread\"></div>
      <script type=\"text/javascript\">
@@ -24,4 +21,5 @@
      <a href=\"http://disqus.com\" class=\"dsq-brlink\">comments powered by <span class=\"logo-disqus\">Disqus</span></a>")
 
 (defun enable (&key shortname)
-  (coleslaw:add-injection (format nil *disqus-header* shortname) :head))
+  (coleslaw:add-injection (list (format nil *disqus-header* shortname)
+                                (lambda (x) (typep x post))) :head))
diff --git a/plugins/import.lisp b/plugins/import.lisp
index 0b80c55..83d5f0e 100644
--- a/plugins/import.lisp
+++ b/plugins/import.lisp
@@ -53,8 +53,12 @@
     (format out "~A~%" (regex-replace-all (string #\Newline) content "<br>"))))
 
 (defun import-posts (filepath &optional since)
-  (let* ((xml (cxml:parse-file filepath (cxml-dom:make-dom-builder)))
-         (posts (dom:get-elements-by-tag-name xml "item")))
-    (load-config)
+  (when (probe-file filepath)
     (ensure-directories-exist (repo *config*))
-    (loop for post across posts do (import-post post since))))
+    (let* ((xml (cxml:parse-file filepath (cxml-dom:make-dom-builder)))
+           (posts (dom:get-elements-by-tag-name xml "item")))
+      (loop for post across posts do (import-post post since))
+      (delete-file filepath))))
+
+(defun enable (&key filepath)
+  (import-posts filepath))
diff --git a/plugins/mathjax.lisp b/plugins/mathjax.lisp
index 360c95d..0ab1896 100644
--- a/plugins/mathjax.lisp
+++ b/plugins/mathjax.lisp
@@ -15,4 +15,10 @@ src=\"http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLor
 </script>")
 
 (defun enable ()
-  (coleslaw:add-injection *mathjax-header* :head))
+  (labels ((math-post-p (post)
+             (member "math" (post-tags post) :test #'string=))
+           (mathjax-p (content)
+             (etypecase content
+               (post (math-post-p content))
+               (index (some #'math-post-p (index-posts content))))))
+    (coleslaw:add-injection (list *mathjax-header* #'mathjax-p) :head)))