diff --git a/src/simudator/processor/mia/modules/ir.py b/src/simudator/processor/mia/modules/ir.py
index c3224a8adbd1ef68692e604e7f2e897becafba64..a5202abd5b770f175606a2820dac291b291c9c5b 100644
--- a/src/simudator/processor/mia/modules/ir.py
+++ b/src/simudator/processor/mia/modules/ir.py
@@ -12,6 +12,12 @@ class IR(Module, MiaBusConnector):
     several fields.
     """
 
+    __slots__ = (
+        ("op", "grx", "m", "a", "instruction")
+        + Module.__slots__
+        + MiaBusConnector.__slots__
+    )
+
     def __init__(
         self,
         to_bus: Signal,
@@ -24,8 +30,6 @@ class IR(Module, MiaBusConnector):
         bus_id=0,
         name: str = "IR",
     ) -> None:
-        MiaBusConnector.__init__(self, bus_control, bus_id)
-
         signals = {
             "in_input": from_bus,
             "out_output": to_bus,
@@ -34,6 +38,7 @@ class IR(Module, MiaBusConnector):
             "out_m": m_s,
         }
         Module.__init__(self, signals, name)
+        MiaBusConnector.__init__(self, bus_control, bus_id)
 
         # Internal values
         self.op = 0
@@ -141,4 +146,3 @@ class IR(Module, MiaBusConnector):
         string_pair = state_string.split(": ")
         # TODO: Maybe check if it starts with instruction: ?
         self.instruction = int(string_pair[1], 16)
-