diff --git a/src/raspikeyer.cpp b/src/raspikeyer.cpp
index 20757b9..f0d620e 100644
--- a/src/raspikeyer.cpp
+++ b/src/raspikeyer.cpp
@@ -173,7 +173,7 @@ int main()
                 settings.mode = Mode::Straight;
                 break;
             default:
-                break;
+                std::unreachable();
             }
 
             keyerQueueData.cmd = KeyerQueueCommand::Config;