diff --git a/puml-mode.el b/puml-mode.el
index d4f30eb..9cc2421 100644
--- a/puml-mode.el
+++ b/puml-mode.el
@@ -124,9 +124,11 @@
 (defconst puml-preview-buffer "*PUML Preview*")
 
 (defvar puml-output-type
-  (cond ((image-type-available-p 'svg) "svg")
-        ((image-type-available-p 'png) "png")
-        (t "utxt"))
+  (if (not (display-images-p))
+      "utxt"
+    (cond ((image-type-available-p 'svg) "svg")
+	  ((image-type-available-p 'png) "png")
+	  (t "utxt")))
   "Specify the desired output type to use for generated diagrams.")
 
 (defun puml-read-output-type ()