diff --git a/rosella.c b/rosella.c
index 5f03a62..f455805 100644
--- a/rosella.c
+++ b/rosella.c
@@ -175,6 +175,10 @@ static void print_value(value_t v)
   {
     fputs("#t", stdout);
   }
+  else if (v == UNDEFINED)
+  {
+    fputs("#<undefined>", stdout);
+  }
   else if (is_fixnum(v))
   {
     printf("%d", (int)get_fixnum(v));