diff --git a/gridappsd-python-lib/gridappsd/json_extension.py b/gridappsd-python-lib/gridappsd/json_extension.py
index 81d7343..692d0c6 100644
--- a/gridappsd-python-lib/gridappsd/json_extension.py
+++ b/gridappsd-python-lib/gridappsd/json_extension.py
@@ -34,20 +34,90 @@ def default(self, obj: Any) -> Any:
         return rv
 
 
-def dump(data: Any, fo: TextIO):
-    rv = _json.dump(data, fo, cls=JsonEncoderExtension)
+def dump(data: Any,
+         fo: TextIO,
+         *,
+         skipkeys=False,
+         ensure_ascii=True,
+         check_circular=True,
+         allow_nan=True,
+         indent=None,
+         separators=None,
+         default=None,
+         sort_keys=False,
+         **kw):
+    rv = _json.dump(data,
+                    fo,
+                    skipkeys=skipkeys,
+                    ensure_ascii=ensure_ascii,
+                    check_circular=check_circular,
+                    allow_nan=allow_nan,
+                    cls=JsonEncoderExtension,
+                    indent=indent,
+                    separators=separators,
+                    default=default,
+                    sort_keys=sort_keys,
+                    **kw)
 
 
-def dumps(data: Any) -> str:
-    rv = _json.dumps(data, cls=JsonEncoderExtension)
+def dumps(data: Any,
+          *,
+          skipkeys=False,
+          ensure_ascii=True,
+          check_circular=True,
+          allow_nan=True,
+          indent=None,
+          separators=None,
+          default=None,
+          sort_keys=False,
+          **kw) -> str:
+    rv = _json.dumps(data,
+                     skipkeys=skipkeys,
+                     ensure_ascii=ensure_ascii,
+                     check_circular=check_circular,
+                     allow_nan=allow_nan,
+                     cls=JsonEncoderExtension,
+                     indent=indent,
+                     separators=separators,
+                     default=default,
+                     sort_keys=sort_keys,
+                     **kw)
     return rv
 
 
-def load(fo: TextIO) -> Any:
-    rv = _json.load(fo, object_hook=jsonDecoderExtension)
+def load(fo: TextIO,
+         *,
+         cls=None,
+         parse_float=None,
+         parse_int=None,
+         parse_constant=None,
+         object_pairs_hook=None,
+         **kw) -> Any:
+    rv = _json.load(fo,
+                    cls=cls,
+                    object_hook=jsonDecoderExtension,
+                    parse_float=parse_float,
+                    parse_int=parse_int,
+                    parse_constant=parse_constant,
+                    object_pairs_hook=object_pairs_hook,
+                    **kw)
     return rv
 
 
-def loads(data: str) -> Any:
-    rv = _json.loads(data, object_hook=jsonDecoderExtension)
+def loads(data: str,
+          *,
+          cls=None,
+          parse_float=None,
+          parse_int=None,
+          parse_constant=None,
+          object_pairs_hook=None,
+          **kw) -> Any:
+    rv = _json.loads(data,
+                     cls=cls,
+                     object_hook=jsonDecoderExtension,
+                     parse_float=parse_float,
+                     parse_int=parse_int,
+                     parse_constant=parse_constant,
+                     object_pairs_hook=object_pairs_hook,
+                     **kw)
     return rv
diff --git a/gridappsd-python-lib/gridappsd/simulation.py b/gridappsd-python-lib/gridappsd/simulation.py
index 8ff94b0..2c074ad 100644
--- a/gridappsd-python-lib/gridappsd/simulation.py
+++ b/gridappsd-python-lib/gridappsd/simulation.py
@@ -122,8 +122,12 @@ class Simulation:
 
     def __init__(self, gapps: 'GridAPPSD', run_config: Union[Dict, SimulationConfig]):
         assert type(gapps).__name__ == 'GridAPPSD', "Must be an instance of GridAPPSD"
-
-        self._run_config = run_config
+        if isinstance(run_config, SimulationConfig):
+            self._run_config = run_config.asdict()
+        elif isinstance(run_config, dict):
+            self._run_config = run_config
+        else:
+            raise TypeError("run_config must be a dictionary or a SimulationConfig")
         # if isinstance(run_config, SimulationConfig):
         #     self._run_config = run_config
         # else: