diff --git a/python/cocotbext/cocotbext/ofm/mfb/monitors.py b/python/cocotbext/cocotbext/ofm/mfb/monitors.py
index 9e1606414..159b9637f 100644
--- a/python/cocotbext/cocotbext/ofm/mfb/monitors.py
+++ b/python/cocotbext/cocotbext/ofm/mfb/monitors.py
@@ -102,7 +102,7 @@ async def _monitor_recv(self):
                         # Checking for beginning of a packet.
                         self.log.debug("Frame Start")
                         if in_frame:
-                            raise MFBProtocolError("Duplicate start-of-frame received on MFB bus!")
+                            raise MFBProtocolError("MFB error: a start-of-frame received without an end-of-frame!")
                         in_frame = True
                         frame = b""
 
@@ -110,7 +110,7 @@ async def _monitor_recv(self):
                             # Checking if the packet ends in the same regions where it began.
                             self.log.debug("Frame End in single region")
                             if not in_frame:
-                                raise MFBProtocolError("Duplicate end-of-frame received on MFB bus!")
+                                raise MFBProtocolError("MFB error: an end-of-frame received without a start-of-frame!")
                             in_frame = False
                             frame += data_bytes[ss_idx:ee_idx]
                             self.item_cnt += len(data_bytes[ss_idx:ee_idx])*8 // self._item_width