diff --git a/vunit/configuration.py b/vunit/configuration.py
index 874aaec42..5c16665de 100644
--- a/vunit/configuration.py
+++ b/vunit/configuration.py
@@ -199,13 +199,18 @@ def set_generic(self, name, value):
             for config in configs.values():
                 config.set_generic(name, value)
 
-    def set_sim_option(self, name, value):
+    def set_sim_option(self, name, value, overwrite=True):
         """
         Set sim option
+
+        :param overwrite: To overwrite the option or append to the existing value
         """
         self._check_enabled()
         for configs in self.get_configuration_dicts():
             for config in configs.values():
+                if not overwrite:
+                    config.set_sim_option(name, config.sim_options.get(name, []) + value)
+                    continue
                 config.set_sim_option(name, value)
 
     def set_pre_config(self, value):
diff --git a/vunit/ui.py b/vunit/ui.py
index 3ba99b9b9..d4d080d90 100644
--- a/vunit/ui.py
+++ b/vunit/ui.py
@@ -564,13 +564,14 @@ def set_parameter(self, name, value, allow_empty=False):
         for test_bench in check_not_empty(test_benches, allow_empty, "No test benches found"):
             test_bench.set_generic(name, value)
 
-    def set_sim_option(self, name, value, allow_empty=False):
+    def set_sim_option(self, name, value, allow_empty=False, overwrite=True):
         """
         Set simulation option in all |configurations|
 
         :param name: |simulation_options|
         :param value: The value of the simulation option
         :param allow_empty: To disable an error when no test benches were found
+        :param overwrite: To overwrite the option or append to the existing value
 
         :example:
 
@@ -583,7 +584,7 @@ def set_sim_option(self, name, value, allow_empty=False):
         """
         test_benches = self._test_bench_list.get_test_benches()
         for test_bench in check_not_empty(test_benches, allow_empty, "No test benches found"):
-            test_bench.set_sim_option(name, value)
+            test_bench.set_sim_option(name, value, overwrite)
 
     def set_compile_option(self, name, value, allow_empty=False):
         """
@@ -1194,13 +1195,14 @@ def set_parameter(self, name, value, allow_empty=False):
         for test_bench in self.get_test_benches(allow_empty=allow_empty):
             test_bench.set_generic(name, value)
 
-    def set_sim_option(self, name, value, allow_empty=False):
+    def set_sim_option(self, name, value, allow_empty=False, overwrite=True):
         """
-        Set simlation option within all |configurations| of test benches and tests this library
+        Set simulation option within all |configurations| of test benches and tests this library
 
         :param name: |simulation_options|
         :param value: The value of the simulation option
         :param allow_empty: To disable an error when no test benches were found
+        :param overwrite: To overwrite the option or append to the existing value
 
         :example:
 
@@ -1212,7 +1214,7 @@ def set_sim_option(self, name, value, allow_empty=False):
            Only affects test benches added *before* the option is set.
         """
         for test_bench in self.get_test_benches(allow_empty=allow_empty):
-            test_bench.set_sim_option(name, value)
+            test_bench.set_sim_option(name, value, overwrite)
 
     def set_compile_option(self, name, value, allow_empty=False):
         """
@@ -1506,12 +1508,13 @@ def set_parameter(self, name, value):
         """
         self._test_bench.set_generic(name, value)
 
-    def set_sim_option(self, name, value):
+    def set_sim_option(self, name, value, overwrite=True):
         """
         Set simulation option within all |configurations| of this test bench or test cases within it
 
         :param name: |simulation_options|
         :param value: The value of the simulation option
+        :param overwrite: To overwrite the option or append to the existing value
 
         :example:
 
@@ -1520,7 +1523,7 @@ def set_sim_option(self, name, value):
            test_bench.set_sim_option("ghdl.flags", ["--no-vital-checks"])
 
         """
-        self._test_bench.set_sim_option(name, value)
+        self._test_bench.set_sim_option(name, value, overwrite)
 
     def set_pre_config(self, value):
         """
@@ -1786,12 +1789,13 @@ def set_parameter(self, name, value):
         """
         self._test_case.set_generic(name, value)
 
-    def set_sim_option(self, name, value):
+    def set_sim_option(self, name, value, overwrite=True):
         """
         Set simulation option within all |configurations| of this test
 
         :param name: |simulation_options|
         :param value: The value of the simulation option
+        :param overwrite: To overwrite the option or append to the existing value
 
         :example:
 
@@ -1800,7 +1804,7 @@ def set_sim_option(self, name, value):
            test.set_sim_option("ghdl.flags", ["--no-vital-checks"])
 
         """
-        self._test_case.set_sim_option(name, value)
+        self._test_case.set_sim_option(name, value, overwrite)
 
     def set_pre_config(self, value):
         """