diff --git a/ansi-tests/fill.lsp b/ansi-tests/fill.lsp
index 0b5d9b0246bb661912fe6f108406a823dc0e8e6e..c6facb4b8fcd81e7b194bcc6a40b587507044c4a 100644
--- a/ansi-tests/fill.lsp
+++ b/ansi-tests/fill.lsp
@@ -5,6 +5,10 @@
 
 (in-package :cl-test)
 
+(deftest fill-error.1
+  (classify-error (fill 'a 'b))
+  type-error)
+
 ;;; Fill on arrays
 
 (deftest array-fill-1