diff --git a/collects/tests/mzscheme/rx.ss b/collects/tests/mzscheme/rx.ss
index 50ad4171ef..4babe3a30a 100644
--- a/collects/tests/mzscheme/rx.ss
+++ b/collects/tests/mzscheme/rx.ss
@@ -873,6 +873,8 @@
        #"{}"
        #"{}"
        (#"|" #"x" (#""))
+       (#"|x" #"x" (#""))
+       (#"x|" #"x" (#"x"))
        (#"\0000" #"\0000" (#"\0\x30"))
        (#"a(?<=)b" #"ab" (#"ab"))
        (#"a(?i:b)" #"ab" (#"ab"))