diff --git a/src/DynareBison.yy b/src/DynareBison.yy
index 2e2087da7c814acfee1e7d1441f0047c8c871fa4..4253c7c3640ea0c54d94ebcb571f7c85ececbcd0 100644
--- a/src/DynareBison.yy
+++ b/src/DynareBison.yy
@@ -117,7 +117,7 @@ str_tolower(string s)
 %token LAPLACE LIK_INIT LINEAR LINEAR_DECOMPOSITION LOAD_IDENT_FILES LOAD_MH_FILE LOAD_RESULTS_AFTER_LOAD_MH LOAD_PARAMS_AND_STEADY_STATE LOGLINEAR LOGDATA LYAPUNOV LINEAR_APPROXIMATION
 %token LYAPUNOV_COMPLEX_THRESHOLD LYAPUNOV_FIXED_POINT_TOL LYAPUNOV_DOUBLING_TOL LOG_DEFLATOR LOG_TREND_VAR LOG_GROWTH_FACTOR
 %token MATCHED_MOMENTS MARKOWITZ MARGINAL_DENSITY MAX MAXIT
-%token MFS MH_CONF_SIG MH_DROP MH_INIT_SCALE MH_INIT_SCALE_FACTOR MH_JSCALE MH_TUNE_JSCALE MH_TUNE_GUESS MH_POSTERIOR_MODE_ESTIMATION MH_NBLOCKS MH_REPLIC MH_RECOVER MH_INITIALIZE_FROM_PREVIOUS_MCMC MH_INITIALIZE_FROM_PREVIOUS_MCMC_DIRECTORY MH_INITIALIZE_FROM_PREVIOUS_MCMC_RECORD MH_INITIALIZE_FROM_PREVIOUS_MCMC_PRIOR
+%token MH_CONF_SIG MH_DROP MH_INIT_SCALE MH_INIT_SCALE_FACTOR MH_JSCALE MH_TUNE_JSCALE MH_TUNE_GUESS MH_POSTERIOR_MODE_ESTIMATION MH_NBLOCKS MH_REPLIC MH_RECOVER MH_INITIALIZE_FROM_PREVIOUS_MCMC MH_INITIALIZE_FROM_PREVIOUS_MCMC_DIRECTORY MH_INITIALIZE_FROM_PREVIOUS_MCMC_RECORD MH_INITIALIZE_FROM_PREVIOUS_MCMC_PRIOR
 %token POSTERIOR_MAX_SUBSAMPLE_DRAWS MIN MINIMAL_SOLVING_PERIODS
 %token MODE_CHECK MODE_CHECK_NEIGHBOURHOOD_SIZE MODE_CHECK_SYMMETRIC_PLOTS MODE_CHECK_NUMBER_OF_POINTS MODE_COMPUTE MODE_FILE MODEL MODEL_COMPARISON MODEL_INFO MSHOCKS ABS SIGN
 %token MODEL_DIAGNOSTICS MODIFIEDHARMONICMEAN MOMENTS_VARENDO CONTEMPORANEOUS_CORRELATION DIFFUSE_FILTER SUB_DRAWS TAPER_STEPS GEWEKE_INTERVAL RAFTERY_LEWIS_QRS RAFTERY_LEWIS_DIAGNOSTICS BROOKS_GELMAN_PLOTROWS MCMC_JUMPING_COVARIANCE MOMENT_CALIBRATION
@@ -170,7 +170,7 @@ str_tolower(string s)
 %token VLISTLOG VLISTPER SPECTRAL_DENSITY INIT2SHOCKS
 %token RESTRICTION RESTRICTION_FNAME CROSS_RESTRICTIONS NLAGS CONTEMP_REDUCED_FORM REAL_PSEUDO_FORECAST
 %token DUMMY_OBS NSTATES INDXSCALESSTATES NO_BAYESIAN_PRIOR SPECIFICATION SIMS_ZHA
-%token <string> ALPHA BETA ABAND NINV CMS NCMS CNUM GAMMA INV_GAMMA INV_GAMMA1 INV_GAMMA2 NORMAL UNIFORM EPS PDF FIG DR NONE PRIOR PRIOR_VARIANCE HESSIAN IDENTITY_MATRIX DIRICHLET DIAGONAL OPTIMAL
+%token <string> ALPHA BETA ABAND NINV CMS NCMS CNUM GAMMA INV_GAMMA INV_GAMMA1 INV_GAMMA2 NORMAL UNIFORM EPS PDF FIG DR NONE PRIOR PRIOR_VARIANCE HESSIAN IDENTITY_MATRIX DIRICHLET DIAGONAL OPTIMAL MFS
 %token GSIG2_LMDM Q_DIAG FLAT_PRIOR NCSK NSTD WEIBULL WEIBULL_PDF
 %token INDXPARR INDXOVR INDXAP APBAND INDXIMF INDXFORE FOREBAND INDXGFOREHAT INDXGIMFHAT
 %token INDXESTIMA INDXGDLS EQ_MS FILTER_COVARIANCE UPDATED_COVARIANCE FILTER_DECOMPOSITION SMOOTHED_STATE_UNCERTAINTY SMOOTHER_REDUX
@@ -4560,6 +4560,7 @@ symbol : NAME
        | DD
        | ADD
        | MULTIPLY
+       | MFS
        ;
 
 %%
diff --git a/src/DynareFlex.ll b/src/DynareFlex.ll
index 5fceacf4068f01998043583ce8bfa14df483161d..646a140998f250bc2c27bfb4dd55f2cbb7061e06 100644
--- a/src/DynareFlex.ll
+++ b/src/DynareFlex.ll
@@ -804,7 +804,10 @@ DATE -?[0-9]+([ya]|m([1-9]|1[0-2])|q[1-4])
   return token::MULTIPLY;
 }
 <DYNARE_STATEMENT,DYNARE_BLOCK>cutoff {return token::CUTOFF;}
-<DYNARE_STATEMENT,DYNARE_BLOCK>mfs {return token::MFS;}
+<DYNARE_STATEMENT,DYNARE_BLOCK>mfs {
+  yylval->build<string>(yytext);
+  return token::MFS;
+}
 <DYNARE_STATEMENT,DYNARE_BLOCK>static_mfs {return token::STATIC_MFS;}
 <DYNARE_STATEMENT,DYNARE_BLOCK>balanced_growth_test_tol {return token::BALANCED_GROWTH_TEST_TOL;}
 <DYNARE_BLOCK>gamma_pdf {return token::GAMMA_PDF;}