diff --git a/decoder/src/Decoder.cpp b/decoder/src/Decoder.cpp
index 291da6b5de7de8c8b0ff2b0b17a0007ee491a289..e7b2285363208b1607f5143aa9ba7d092e4e20c7 100644
--- a/decoder/src/Decoder.cpp
+++ b/decoder/src/Decoder.cpp
@@ -34,13 +34,19 @@ void Decoder::decode(BaseConfig & config, std::size_t beamSize, bool debug)
       for (unsigned int i = 0; i < prediction.size(0); i++)
       {
         float score = prediction[i].item<float>();
-        if (score > bestScore and machine.getTransitionSet().getTransition(i)->appliable(config))
+        if ((chosenTransition == -1 or score > bestScore) and machine.getTransitionSet().getTransition(i)->appliable(config))
+        {
           chosenTransition = i;
+          bestScore = score;
+        }
       }
     } catch(std::exception & e) {util::myThrow(e.what());}
 
     if (chosenTransition == -1)
+    {
+      config.printForDebug(stderr);
       util::myThrow("No transition appliable !");
+    }
 
     auto * transition = machine.getTransitionSet().getTransition(chosenTransition);