diff --git a/src/python_spectrometer/daq/simulator.py b/src/python_spectrometer/daq/simulator.py
index 8699b64a04c73b263cd6795bc378932f49509eb6..7e27984f21b045c618b48f4ea79b2cb0b1949400 100644
--- a/src/python_spectrometer/daq/simulator.py
+++ b/src/python_spectrometer/daq/simulator.py
@@ -78,19 +78,16 @@ def with_delay(meth):
                 yield data
 
     # Insert parameter sig
-    meth_sig = inspect.signature(meth)
-    wrapped_sig = inspect.signature(wrapped)
-
     delay_param = inspect.Parameter('delay', inspect.Parameter.KEYWORD_ONLY, default=True,
                                     annotation=bool | float)
 
-    parameters = list(meth_sig.parameters.values())
+    parameters = list(inspect.signature(meth).parameters.values())
     if parameters[-1].kind is inspect.Parameter.VAR_KEYWORD:
         parameters = parameters[:-1] + [delay_param, parameters[-1]]
     else:
         parameters = parameters + [delay_param]
 
-    wrapped.__signature__ = wrapped_sig.replace(parameters=parameters)
+    wrapped.__signature__ = inspect.signature(wrapped).replace(parameters=parameters)
     return wrapped