diff --git a/reading_machine/src/Transition.cpp b/reading_machine/src/Transition.cpp
index 2e0cab4f86256c6ac44fd641b9df9847e11a2e55..1b8d309fceee9527550389ff5ee6b3b66d482240 100644
--- a/reading_machine/src/Transition.cpp
+++ b/reading_machine/src/Transition.cpp
@@ -329,7 +329,7 @@ void Transition::initSplitWord(std::vector<std::string> words)
       return std::numeric_limits<int>::max();
 
     for (unsigned int i = 0; i < words.size(); i++)
-      if (!config.has("FORM", config.getWordIndex()+i, 0) or util::lower(config.getConst("FORM", config.getWordIndex()+i, 0)) != words[i])
+      if (!config.has("FORM", config.getWordIndex()+i, 0) or util::lower(config.getConst("FORM", config.getWordIndex()+i, 0)) != util::lower(words[i]))
         return std::numeric_limits<int>::max();
 
     return 0;