diff --git a/pyphare/pyphare/simulator/simulator.py b/pyphare/pyphare/simulator/simulator.py
index 435d7b01d..bb812bd7f 100644
--- a/pyphare/pyphare/simulator/simulator.py
+++ b/pyphare/pyphare/simulator/simulator.py
@@ -3,6 +3,7 @@
 #
 
 import os
+import sys
 import datetime
 import atexit
 import time as timem
@@ -91,7 +92,7 @@ def __init__(self, simulation, auto_dump=True, **kwargs):
         self.cpp_sim = None  # BE
         self.cpp_dw = None  # DRAGONS, i.e. use weakrefs if you have to ref these.
         self.post_advance = kwargs.get("post_advance", None)
-
+        self.initialized = False
         self.print_eol = "\n"
         if kwargs.get("print_one_line", True):
             self.print_eol = "\r"
@@ -132,7 +133,6 @@ def setup(self):
             )
             return self
         except Exception:
-            import sys
             import traceback
 
             print('Exception caught in "Simulator.setup()": {}'.format(sys.exc_info()))
@@ -140,11 +140,9 @@ def setup(self):
             raise ValueError("Error in Simulator.setup(), see previous error")
 
     def initialize(self):
-        if self.cpp_sim is not None:
-            raise ValueError(
-                "Simulator already initialized: requires reset to re-initialize"
-            )
         try:
+            if self.initialized:
+                return
             if self.cpp_hier is None:
                 self.setup()
 
@@ -152,12 +150,11 @@ def initialize(self):
                 return self
 
             self.cpp_sim.initialize()
+            self.initialized = True
             self._auto_dump()  # first dump might be before first advance
 
             return self
         except Exception:
-            import sys
-
             print(
                 'Exception caught in "Simulator.initialize()": {}'.format(
                     sys.exc_info()[0]
@@ -166,8 +163,6 @@ def initialize(self):
             raise ValueError("Error in Simulator.initialize(), see previous error")
 
     def _throw(self, e):
-        import sys
-
         print_rank0(e)
         sys.exit(1)
 
@@ -264,6 +259,7 @@ def reset(self):
         self.cpp_dw = None
         self.cpp_sim = None
         self.cpp_hier = None
+        self.initialized = False
         if "samrai" in life_cycles:
             type(life_cycles["samrai"]).reset()
         return self
@@ -289,7 +285,7 @@ def interp_order(self):
         return self.cpp_sim.interp_order  # constexpr static value
 
     def _check_init(self):
-        if self.cpp_sim is None:
+        if not self.initialized:
             self.initialize()
 
     def _log_to_file(self):