diff --git a/tests/arima/mod2a.mod b/tests/arima/mod2a.mod
index 9414afa90..bc9ebc369 100644
--- a/tests/arima/mod2a.mod
+++ b/tests/arima/mod2a.mod
@@ -29,5 +29,5 @@ end;
 
 varobs dx dy;
 
-options_.unit_root_vars = {'x'; 'y'};
+unit_root_vars x y;
 estimation(datafile=data2,nobs=100,mh_replic=0,lik_init=2);
diff --git a/tests/arima/mod2b.mod b/tests/arima/mod2b.mod
index d2465a22c..d766269ca 100644
--- a/tests/arima/mod2b.mod
+++ b/tests/arima/mod2b.mod
@@ -29,5 +29,5 @@ end;
 
 varobs x y;
 
-options_.unit_root_vars = {'x'; 'y'};
+unit_root_vars x y;
 estimation(datafile=data2,nobs=100,mh_replic=0,lik_init=2);
diff --git a/tests/fs2000/fs2000b.mod b/tests/fs2000/fs2000b.mod
index fdb95988c..f6b2c2016 100644
--- a/tests/fs2000/fs2000b.mod
+++ b/tests/fs2000/fs2000b.mod
@@ -95,7 +95,7 @@ P_obs (log(mst)-gam);
 Y_obs (gam);
 end;
 
-options_.unit_root_vars = {'P_obs'; 'Y_obs'};
+unit_root_vars P_obs Y_obs;
 
 //stoch_simul(order=1,nomoments,irf=0);
 estimation(datafile=fsdat,nobs=192,loglinear,mh_replic=0,mh_nblocks=2,mh_drop=0.45,mode_compute=0,mode_file=fs2000b_mode,load_mh_file);