diff --git a/doc/dynare.texi b/doc/dynare.texi
index b614c2a22d04a5e7af6b51e157d4fb763020cde7..5c500ff66c4188e9817bb9105bbe497b23cd288f 100644
--- a/doc/dynare.texi
+++ b/doc/dynare.texi
@@ -8698,13 +8698,14 @@ The number of data points included in the output. Default: @code{0}
 @xref{regime}.
 
 @item regimes
-
 @xref{regimes}.
 
 @item median
-
 @xref{median}.
 
+@item horizon = @var{INTEGER}
+@xref{horizon}.
+
 @end table
 
 @end deffn
diff --git a/preprocessor/DynareBison.yy b/preprocessor/DynareBison.yy
index f60ffa7a64c896962727db8620c6f85fad9f1e46..1b99af33a40afaaae594e77eed0c6f6f7136ca71 100644
--- a/preprocessor/DynareBison.yy
+++ b/preprocessor/DynareBison.yy
@@ -2145,6 +2145,7 @@ ms_forecast_option : o_output_file_tag
                    | o_regime
                    | o_regimes
                    | o_parameter_uncertainty
+                   | o_horizon
                    ;
 
 ms_forecast_options_list : ms_forecast_option COMMA ms_forecast_options_list