diff --git a/lisp/langs/org-babel-css.el b/lisp/langs/org-babel-css.el
index 836870f36..93a369dc8 100644
--- a/lisp/langs/org-babel-css.el
+++ b/lisp/langs/org-babel-css.el
@@ -34,7 +34,7 @@
 
 (org-babel-add-interpreter "css")
 
-(add-to-list 'org-babel-tangle-langs '("css" "css"))
+(add-to-list 'org-babel-tangle-langs '("css" "css" nil t))
 
 (defun org-babel-execute:css (body params)
   "Execute a block of CSS code with org-babel.  This function is
diff --git a/lisp/org-babel-tangle.el b/lisp/org-babel-tangle.el
index 2767caaa0..3cf34e4f7 100644
--- a/lisp/org-babel-tangle.el
+++ b/lisp/org-babel-tangle.el
@@ -35,8 +35,9 @@
   "Association list matching source-block languages.  The car of
 each element should be a string indicating the source block
 language, and the cdr should be a list containing the extension
-and shebang(#!) line to use when writing out the language to
-file.")
+shebang(#!) line to use when writing out the language to file,
+and an optional flag indicating that the language is not
+commentable.")
 
 (defun org-babel-load-file (file)
   "Load the contents of the Emacs Lisp source code blocks in the
@@ -80,7 +81,8 @@ exported source code blocks by language."
                 (lang-f (intern (concat lang "-mode")))
                 (lang-specs (cdr (assoc lang org-babel-tangle-langs)))
                 (ext (first lang-specs))
-                (she-bang (second lang-specs)))
+                (she-bang (second lang-specs))
+                (commentable (not (third lang-specs))))
            (mapc
             (lambda (spec)
               (let* ((tangle (cdr (assoc :tangle (third spec))))
@@ -104,8 +106,9 @@ exported source code blocks by language."
                   (with-temp-buffer
                     (funcall lang-f)
                     (when she-bang (insert (concat she-bang "\n")))
-                    (comment-region
-                     (point) (progn (insert "generated by org-babel-tangle") (point)))
+                    (when commentable
+                      (comment-region
+                       (point) (progn (insert "generated by org-babel-tangle") (point))))
                     (org-babel-spec-to-string spec)
                     (append-to-file nil nil file-name))
                   ;; update counter
@@ -134,7 +137,7 @@ code blocks by language."
              (src-lang (first info))
              (body (org-babel-expand-noweb-references info))
              (params (third info))
-             (spec (list link source-name params body))
+             (spec (list link source-name params body (third (cdr (assoc src-lang org-babel-tangle-langs)))))
              by-lang)
         (unless (string= (cdr (assoc :tangle params)) "no") ;; maybe skip
           (unless (and lang (not (string= lang src-lang))) ;; maybe limit by language
@@ -146,7 +149,7 @@ code blocks by language."
     (setq blocks
           (mapcar (lambda (by-lang) (cons (car by-lang) (reverse (cdr by-lang)))) blocks))
     ;; blocks should contain all source-blocks organized by language
-    (message "blocks=%S" blocks) ;; debugging
+    ;; (message "blocks=%S" blocks) ;; debugging
     blocks))
 
 (defun org-babel-spec-to-string (spec)
@@ -157,10 +160,12 @@ form
 
   (link source-name params body)"
   (flet ((insert-comment (text)
-                         (comment-region (point) (progn (insert text) (point)))))
+                         (when commentable
+                           (comment-region (point) (progn (insert text) (point))))))
     (let ((link (first spec))
           (source-name (second spec))
-          (body (fourth spec)))
+          (body (fourth spec))
+          (commentable (not (fifth spec))))
       (insert "\n\n")
       (insert-comment (format "[[%s][%s]]" (org-link-escape link) source-name))
       (insert (format "\n%s\n" (org-babel-chomp body)))