diff --git a/transition_machine/src/ActionBank.cpp b/transition_machine/src/ActionBank.cpp
index 6977f3ac5af42839b5f0d7f76fad623fc445a4dc..753a663580feab36c7531b354748d920139bcd63 100644
--- a/transition_machine/src/ActionBank.cpp
+++ b/transition_machine/src/ActionBank.cpp
@@ -769,10 +769,10 @@ std::vector<Action::BasicAction> ActionBank::str2sequence(const std::string & na
           // Attaching floating words to new root
           int sentenceEnd = b0;
           auto & eos = c.getTape(ProgramParameters::sequenceDelimiterTape);
-          while (sentenceEnd >= 0 && eos[sentenceEnd-b0] != ProgramParameters::sequenceDelimiter)
+          while (sentenceEnd >= 0 && eos.getHyp(sentenceEnd-b0) != ProgramParameters::sequenceDelimiter)
             sentenceEnd--;
           int sentenceStart = std::max(0,sentenceEnd-1);
-          while (sentenceStart >= 0 && eos[sentenceStart-b0] != ProgramParameters::sequenceDelimiter)
+          while (sentenceStart >= 0 && eos.getHyp(sentenceStart-b0) != ProgramParameters::sequenceDelimiter)
             sentenceStart--;
           sentenceStart++;