diff --git a/tests/extmod/ure1.py b/tests/extmod/ure1.py
index 6075990fcb42b0e9ec379b983aa882c7cbf69982..54471ed4f97c4ff3a3d5b3d06fcf2e8f77fc2fde 100644
--- a/tests/extmod/ure1.py
+++ b/tests/extmod/ure1.py
@@ -48,7 +48,12 @@ m = r.match("d")
 print(m.group(0))
 m = r.match("A")
 print(m.group(0))
+print("===")
 
+# '-' character within character class block
+print(re.match("[-a]+", "-a]d").group(0))
+print(re.match("[a-]+", "-a]d").group(0))
+print("===")
 
 r = re.compile("o+")
 m = r.search("foobar")