diff --git a/tests/hazmat/primitives/test_serialization.py b/tests/hazmat/primitives/test_serialization.py
index acdbbd7..2434ee4 100644
--- a/tests/hazmat/primitives/test_serialization.py
+++ b/tests/hazmat/primitives/test_serialization.py
@@ -811,3 +811,32 @@
         assert key.public_numbers() == ec.EllipticCurvePublicNumbers(
             expected_x, expected_y, ec.SECP256R1()
         )
+
+    def test_load_ssh_public_key_ecdsa_nist_p256_trailing_data(self, backend):
+        ssh_key = (
+            b"ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAy"
+            b"NTYAAABBBGG2MfkHXp0UkxUyllDzWNBAImsvt5t7pFtTXegZK2WbGxml8zMrgWi5"
+            b"teIg1TO03/FD9hbpBFgBeix3NrCFPltB= root@cloud-server-01"
+        )
+        with pytest.raises(ValueError):
+            load_ssh_public_key(ssh_key, backend)
+
+    def test_load_ssh_public_key_ecdsa_nist_p256_missing_data(self, backend):
+        ssh_key = (
+            b"ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAy"
+            b"NTYAAABBBGG2MfkHXp0UkxUyllDzWNBAImsvt5t7pFtTXegZK2WbGxml8zMrgWi5"
+            b"teIg1TO03/FD9hbpBFgBeix3NrCF= root@cloud-server-01"
+        )
+        with pytest.raises(ValueError):
+            load_ssh_public_key(ssh_key, backend)
+
+    def test_load_ssh_public_key_ecdsa_nist_p256_compressed(self, backend):
+        # If we ever implement compressed points, note that this is not a valid
+        # one, it just has the compressed marker in the right place.
+        ssh_key = (
+            b"ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAy"
+            b"NTYAAABBAWG2MfkHXp0UkxUyllDzWNBAImsvt5t7pFtTXegZK2WbGxml8zMrgWi5"
+            b"teIg1TO03/FD9hbpBFgBeix3NrCFPls= root@cloud-server-01"
+        )
+        with pytest.raises(NotImplementedError):
+            load_ssh_public_key(ssh_key, backend)