diff --git a/elisp/ghc-check.el b/elisp/ghc-check.el
index 279c883..06d38f5 100644
--- a/elisp/ghc-check.el
+++ b/elisp/ghc-check.el
@@ -160,8 +160,8 @@ nil            does not display errors/warnings.
 	    errs wrns)
 	(dolist (msg msgs)
 	  (if (string-match "^Warning" msg)
-	      (setq wrns (cons msg wrns))
-	    (setq errs (cons msg errs))))
+	      (ghc-add wrns msg)
+	    (ghc-add errs msg)))
 	(ghc-make-file-msgs :file file :msgs (nconc errs wrns))))))
 
 (defun ghc-display-errors ()
diff --git a/elisp/ghc-doc.el b/elisp/ghc-doc.el
index 2b9754f..f3f1822 100644
--- a/elisp/ghc-doc.el
+++ b/elisp/ghc-doc.el
@@ -70,7 +70,7 @@
 	(i 0)
 	acc)
     (while (< i len)
-      (setq acc (cons (format "-%d-" (aref symbol i)) acc))
+      (ghc-add acc (format "-%d-" (aref symbol i)))
       (setq i (1+ i)))
     (apply 'concat (nreverse acc))))