diff --git a/src/FruDevice.cpp b/src/FruDevice.cpp
index a5e5c80..9ca578d 100644
--- a/src/FruDevice.cpp
+++ b/src/FruDevice.cpp
@@ -209,6 +209,11 @@
                 }
                 devices->emplace(ii, device);
             }
+            else
+            {
+                std::cerr << "Illegal header checksum at bus " << bus
+                          << " address " << ii << "\n";
+            }
         }
         return 1;
     });