diff --git a/conpot/protocols/modbus/modbus_server.py b/conpot/protocols/modbus/modbus_server.py
index 5400b105..e0929bc2 100644
--- a/conpot/protocols/modbus/modbus_server.py
+++ b/conpot/protocols/modbus/modbus_server.py
@@ -134,10 +134,26 @@ def handle(self, sock, address):
                     session.add_event({"type": "CONNECTION_TERMINATED"})
                     break
                 _, _, length = struct.unpack(">HHH", request[:6])
+                previous_request = None
+                stall_counter = 0
+                # Implemented fix proposed by Kevalz95, Issue #564
+                # Adds stall counter to prevent infinite loop on malformed requests
                 while len(request) < (length + 6):
                     try:
+                        # Previous request now assigned before recv() called, length check performed after
+                        previous_request = request
                         new_byte = sock.recv(1)
                         request += new_byte
+                        if previous_request and len(previous_request) == len(request):
+                            stall_counter += 1
+                        if stall_counter >= 1000:
+                            logger.info(
+                                "Modbus client provided data {} but invalid.".format(
+                                    session.id
+                                )
+                            )
+                            session.add_event({"type": "CONNECTION_TERMINATED"})
+                            break
                     except Exception:
                         break
                 query = modbus_tcp.TcpQuery()