diff --git a/test/replace.nim b/test/replace.nim
index ff2c4a2b57..f2fad803dc 100644
--- a/test/replace.nim
+++ b/test/replace.nim
@@ -11,3 +11,6 @@ suite "replace":
     check("123".replace(re"\d", "foo") == "foofoofoo")
     check("123".replace(re"(\d)", "$1$1") == "112233")
     check("123".replace(re"(\d)(\d)", "$1$2") == "123")
+    check("123".replace(re"(\d)(\d)", "$#$#") == "123")
+    check("123".replace(re"(?<foo>\d)(\d)", "$foo$#$#") == "1123")
+    check("123".replace(re"(?<foo>\d)(\d)", "${foo}$#$#") == "1123")