diff --git a/tests/extmod/ssl_cadata.py b/tests/extmod/ssl_cadata.py
new file mode 100644
index 0000000000..a68cae1ecb
--- /dev/null
+++ b/tests/extmod/ssl_cadata.py
@@ -0,0 +1,14 @@
+# Test ssl.wrap_socket() with cadata passed in.
+
+try:
+    import io
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+# Invalid cadata.
+try:
+    ssl.wrap_socket(io.BytesIO(), cadata=b"!")
+except ValueError as er:
+    print(repr(er))
diff --git a/tests/extmod/ssl_cadata.py.exp b/tests/extmod/ssl_cadata.py.exp
new file mode 100644
index 0000000000..9f1cf732e3
--- /dev/null
+++ b/tests/extmod/ssl_cadata.py.exp
@@ -0,0 +1 @@
+ValueError('invalid cert',)