diff --git a/_unittest_solvers/test_00_analyze.py b/_unittest_solvers/test_00_analyze.py
index 580b6305ed5..840ab6ea33e 100644
--- a/_unittest_solvers/test_00_analyze.py
+++ b/_unittest_solvers/test_00_analyze.py
@@ -431,7 +431,6 @@ def test_07_export_maxwell_fields(self, m3dtransient):
         new_setup.props = setup.props
         new_setup.update()
 
-    @pytest.mark.skipif(is_linux, reason="SPISIM is not working in Linux.")
     def test_08_compute_erl(self, circuit_erl):
         touchstone_file = circuit_erl.export_touchstone()
         spisim = SpiSim(touchstone_file)
@@ -453,7 +452,6 @@ def test_08_compute_erl(self, circuit_erl):
         erl_data_3 = spisim.compute_erl(specify_through_ports=[1, 2, 3, 4])
         assert erl_data_3
 
-    @pytest.mark.skipif(is_linux, reason="SPISIM not working in linux.")
     def test_09a_compute_com(self, local_scratch, circuit_com):
         touchstone_file = circuit_com.export_touchstone()
         spisim = SpiSim(touchstone_file)
@@ -466,7 +464,6 @@ def test_09a_compute_com(self, local_scratch, circuit_com):
         )
         assert com
 
-    @pytest.mark.skipif(is_linux, reason="SPISIM not working in linux.")
     def test_09b_compute_com(self, local_scratch):
         com_example_file_folder = os.path.join(local_path, "example_models", test_subfolder, "com_unit_test_sparam")
         thru_s4p = local_scratch.copyfile(os.path.join(com_example_file_folder, "SerDes_Demo_02_Thru.s4p"))
@@ -506,7 +503,7 @@ def test_09b_compute_com(self, local_scratch):
         )
         assert com_0 and com_1
 
-    @pytest.mark.skipif(is_linux, reason="SPISIM not working in linux.")
+
     def test_09c_compute_com(self, local_scratch):
         com_example_file_folder = Path(local_path) / "example_models" / test_subfolder / "com_unit_test_sparam"
         thru_s4p = local_scratch.copyfile(com_example_file_folder / "SerDes_Demo_02_Thru.s4p")
diff --git a/pyaedt/generic/spisim.py b/pyaedt/generic/spisim.py
index 9593205a78f..d2e2f1c1507 100644
--- a/pyaedt/generic/spisim.py
+++ b/pyaedt/generic/spisim.py
@@ -73,6 +73,8 @@ def _compute_spisim(self, parameter, out_file="", touchstone_file="", config_fil
         my_env = os.environ.copy()
         my_env.update(settings.aedt_environment_variables)
         if is_linux:  # pragma: no cover
+            if "ANSYSEM_ROOT_PATH" not in my_env:
+                my_env["ANSYSEM_ROOT_PATH"] = self.desktop_install_dir
             command.append("&")
             with open_file(out_processing, "w") as outfile:
                 subprocess.Popen(command, env=my_env, stdout=outfile, stderr=outfile).wait()  # nosec