diff --git a/doc/dynare.texi b/doc/dynare.texi
index 25d8e5c3f..fb49e72b7 100644
--- a/doc/dynare.texi
+++ b/doc/dynare.texi
@@ -5467,6 +5467,15 @@ calibrated model.
 
 @end table
 
+@vindex oo_.shock_decomposition
+The results are stored in the field @code{oo_.shock_decomposition}, which is a three 
+dimensional array. The first dimension contains the endogenous variables for 
+which the shock decomposition has been requested. The second dimension stores 
+in the first @code{M_.exo_nbr} columns the contribution of the respective shocks. 
+Column @code{M_.exo_nbr+1} stores the contribution of the initial conditions, 
+while column @code{M_.exo_nbr+2} stores the smoothed value of the respective 
+endogenous variable. The third dimension stores the time periods.  
+
 @end deffn
 
 
diff --git a/matlab/shock_decomposition.m b/matlab/shock_decomposition.m
index 34a3b4acf..17bf4c6e2 100644
--- a/matlab/shock_decomposition.m
+++ b/matlab/shock_decomposition.m
@@ -1,6 +1,10 @@
 function oo_ = shock_decomposition(M_,oo_,options_,varlist)
 % function z = shock_decomposition(M_,oo_,options_,varlist)
-% Computes shocks contribution to a simulated trajectory
+% Computes shocks contribution to a simulated trajectory. The field set is
+% oo_.shock_decomposition. It is a n_var by nshock+2 by nperiods array. The
+% first nshock columns store the respective shock contributions, column n+1
+% stores the role of the initial conditions, while column n+2 stores the
+% value of the smoothed variables.
 %
 % INPUTS
 %    M_:          [structure]  Definition of the model