diff --git a/src/DynareFlex.ll b/src/DynareFlex.ll
index 5a79add0ae625e2577c21aa0b6e0658c28913b66..47ccde607f2a1a309c26a223ab60d2d7100c5f59 100644
--- a/src/DynareFlex.ll
+++ b/src/DynareFlex.ll
@@ -437,6 +437,7 @@ DATE -?[0-9]+([ya]|m([1-9]|1[0-2])|q[1-4])
 <DYNARE_STATEMENT>expression    {return token::EXPRESSION;}
 <DYNARE_STATEMENT>occbin_likelihood {return token::OCCBIN_LIKELIHOOD;}
 <DYNARE_STATEMENT>occbin_smoother {return token::OCCBIN_SMOOTHER;}
+<DYNARE_STATEMENT>first_simulation_period {return token::FIRST_SIMULATION_PERIOD;}
 
 <DYNARE_STATEMENT>alpha {
   yylval->build<string>(yytext);