diff --git a/demo.py b/demo.py
index 074c4ae..dc10f1d 100644
--- a/demo.py
+++ b/demo.py
@@ -281,4 +281,9 @@ if __name__ == "__main__":
     parser.add_argument("--gateway", type=str, help="Override the gateway phone number")
 
     args = parser.parse_args()
+    
+    if not args.pdu.startswith("REG-RESP"):
+        print("Invalid REG-RESP PDU")
+        exit(1)
+
     trio.run(main, args)
\ No newline at end of file
diff --git a/sms_registration.py b/sms_registration.py
index fb771b9..c11f7c9 100644
--- a/sms_registration.py
+++ b/sms_registration.py
@@ -21,7 +21,7 @@ def register(push_token: bytes, no_parse = False, gateway = GATEWAY) -> tuple[st
     if no_parse:
         print("Now do the next part and rerun with --pdu")
         exit()
-    parse_pdu(r, req_id)
+    parse_pdu(r.text, req_id)
     
     # if r.text.split("?")[0] != "REG-RESP":
     #     raise Exception(f"Failed to register: {r.text}")
@@ -37,10 +37,10 @@ def register(push_token: bytes, no_parse = False, gateway = GATEWAY) -> tuple[st
     # return resp_params["n"], signature
 
 def parse_pdu(r: str, req_id: int | None = None):
-    if r.text.split("?")[0] != "REG-RESP":
-        raise Exception(f"Failed to register: {r.text}")
+    if r.split("?")[0] != "REG-RESP":
+        raise Exception(f"Failed to register: {r}")
     #assert r.text.split("?")[0] == "REG-RESP"
-    resp_params = r.text.split("?")[1]
+    resp_params = r.split("?")[1]
     resp_params = resp_params.split(";")
     resp_params = {param.split("=")[0]: param.split("=")[1] for param in resp_params}
     assert resp_params["v"] == "3"