diff --git a/transition_machine/src/Config.cpp b/transition_machine/src/Config.cpp
index 7baae4f2b585f1ba802b9486e281532d47f161ef..254da76897d6bca4d9183bde37d8695b67e68fa4 100644
--- a/transition_machine/src/Config.cpp
+++ b/transition_machine/src/Config.cpp
@@ -395,15 +395,15 @@ void Config::printAsOutput(FILE * output, int dataIndex, int realIndex, bool for
     }
     else
     {
-      eosStr = eos.getHyp(dataIndex-head);
-      if (eosStr.empty())
-        eosStr = eos[dataIndex-head];
+      if (eos.getKnown())
+        eosStr = eos.getRef(dataIndex-head);
+      else
+        eosStr = eos.getHyp(dataIndex-head);
     }
 
     if (eosStr == ProgramParameters::sequenceDelimiter)
       fprintf(output, "\n");
   }
-
 }
 
 void Config::moveHead(int mvt)