diff --git a/tests/k_order_perturbation/fs2000k2.mod b/tests/k_order_perturbation/fs2000k2.mod
index 9937be46b9389d39136ce81f778fed934993bd5c..a1997539f0c1946f0c64b1a3cec6e3b822e1d741 100644
--- a/tests/k_order_perturbation/fs2000k2.mod
+++ b/tests/k_order_perturbation/fs2000k2.mod
@@ -67,21 +67,21 @@ dr0 = oo1.oo_.dr;
 dr = oo_.dr;
 
 if max(max(abs(dr0.ghx - dr.ghx))) > 1e-12;
-   disp('error in ghx');
+   error('error in ghx');
 end;
 if max(max(abs(dr0.ghu - dr.ghu))) > 1e-12;
-   disp('error in ghu');
+   error('error in ghu');
 end;
 if max(max(abs(dr0.ghxx - dr.ghxx))) > 1e-12;
-   disp('error in ghxx');
+   error('error in ghxx');
 end;
 if max(max(abs(dr0.ghuu - dr.ghuu))) > 1e-12;
-   disp('error in ghuu');
+   error('error in ghuu');
 end;
 if max(max(abs(dr0.ghxu - dr.ghxu))) > 1e-12;
-   disp('error in ghxu');
+   error('error in ghxu');
 end;
 if max(max(abs(dr0.ghs2 - dr.ghs2))) > 1e-12;
-   disp('error in ghs2');
+   error('error in ghs2');
 end;
 
diff --git a/tests/k_order_perturbation/fs2000k3.mod b/tests/k_order_perturbation/fs2000k3.mod
index 36efd98f3d8e94132cbcf7205bcfa65f982d41ec..a5cab25a1d3c31081f61b89924f362352b58bc50 100644
--- a/tests/k_order_perturbation/fs2000k3.mod
+++ b/tests/k_order_perturbation/fs2000k3.mod
@@ -66,15 +66,15 @@ dr0 = oo1.oo_.dr;
 dr = oo_.dr;
 
 if max(max(abs(dr0.ghxx - dr.ghxx))) > 1e-12;
-   disp('error in ghxx');
+   error('error in ghxx');
 end;
 if max(max(abs(dr0.ghuu - dr.ghuu))) > 1e-12;
-   disp('error in ghuu');
+   error('error in ghuu');
 end;
 if max(max(abs(dr0.ghxu - dr.ghxu))) > 1e-12;
-   disp('error in ghxu');
+   error('error in ghxu');
 end;
 if max(max(abs(dr0.ghs2 - dr.ghs2))) > 1e-12;
-   disp('error in ghs2');
+   error('error in ghs2');
 end;
 
diff --git a/tests/k_order_perturbation/fs2000k_1.mod b/tests/k_order_perturbation/fs2000k_1.mod
index c9e8bb036c12959654633b3945ba838b8a00266c..be201aebc361a2a5f7957d8451cb08a95fdab457 100644
--- a/tests/k_order_perturbation/fs2000k_1.mod
+++ b/tests/k_order_perturbation/fs2000k_1.mod
@@ -78,21 +78,21 @@ ikc2 = [1 3 4 2 9 11 12 10 13 15 16 14 5 7 8 6];
 ikc2u = [1 2 5 6 7 8 3 4];
 
 if max(max(abs(dr0.ghx - dr.ghx(ikr,ikc)))) > 1e-12;
-   disp('error in ghx');
+   error('error in ghx');
 end;
 if max(max(abs(dr0.ghu - dr.ghu(ikr,:)))) > 1e-12;
-   disp('error in ghu');
+   error('error in ghu');
 end;
 if max(max(abs(dr0.ghxx - dr.ghxx(ikr,ikc2)))) > 1e-12;
-   disp('error in ghxx');
+   error('error in ghxx');
 end;
 if max(max(abs(dr0.ghuu - dr.ghuu(ikr,:)))) > 1e-12;
-   disp('error in ghuu');
+   error('error in ghuu');
 end;
 if max(max(abs(dr0.ghxu - dr.ghxu(ikr,ikc2u)))) > 1e-12;
-   disp('error in ghxu');
+   error('error in ghxu');
 end;
 if max(max(abs(dr0.ghs2 - dr.ghs2(ikr,:)))) > 1e-12;
-   disp('error in ghs2');
+   error('error in ghs2');
 end;