diff --git a/ansi-tests/string-right-trim.lsp b/ansi-tests/string-right-trim.lsp
index 66f3e66ba9dea3ae8eb2f01bb71655b80256458e..1706b78e8dd9313419a0845f5da92b6a9fea14da 100644
--- a/ansi-tests/string-right-trim.lsp
+++ b/ansi-tests/string-right-trim.lsp
@@ -213,6 +213,8 @@
      i x y))
   "   abc d e f" 2 1 2)
 
+(def-fold-test string-right-trim.fold.1 (string-right-trim " " "abcd "))
+
 ;;; Error cases
 
 (deftest string-right-trim.error.1