diff --git a/matlab/optimization/dynare_minimize_objective.m b/matlab/optimization/dynare_minimize_objective.m
index ea80ac09139d1c8459f93f57f6bb612ae7fd9236..5466d2330da9871d2e53b743265162a5a78d32f1 100644
--- a/matlab/optimization/dynare_minimize_objective.m
+++ b/matlab/optimization/dynare_minimize_objective.m
@@ -529,7 +529,7 @@ switch minimizer_algorithm
     % Set objective function.
     objfun = @(x) objective_function(x, varargin{:});
     if ischar(particleswarmOptions.SwarmSize)
-        eval(['particleswarmOptions.SwarmSize = ' particleswarmOptions.SwarmSize ';'])
+        particleswarmOptions.SwarmSize = str2num(particleswarmOptions.SwarmSize);
     end
     if isempty(particleswarmOptions.InitialSwarmMatrix)
         particleswarmOptions.InitialSwarmMatrix = zeros(particleswarmOptions.SwarmSize, numberofvariables);