diff --git a/src/inputparser.cpp b/src/inputparser.cpp
index 9f40ca9..dfbfc6d 100644
--- a/src/inputparser.cpp
+++ b/src/inputparser.cpp
@@ -75,7 +75,7 @@ namespace pds {
                             if(config.grammar.variables.find(token.content) == config.grammar.variables.end())
                                 config.grammar.variables.insert(token.content.substr(1, token.content.size() - 2));
                            
-                            std::string current_head = token.content;
+                            std::string current_head = token.content.substr(1, token.content.size() - 2);
                             // Parsing rule
                             token = lex.nextToken();
                             if(token.type != ParsodusLexer::ARROW)