diff --git a/doc/releases/1.15.1dev.rst b/doc/releases/1.15.1dev.rst
index 0e241e1963..818353c391 100644
--- a/doc/releases/1.15.1dev.rst
+++ b/doc/releases/1.15.1dev.rst
@@ -58,3 +58,5 @@ Bug Fixes
   directly a sky spectrum. This fixes a bug in the flexure correction for SlicerIFU.
 - The `--show` option of the `pypeit_coadd_1dspec` script was not properly displaying the
   x-axis of the plot. Both the top and bottom panels now scale together.
+- Fix a bug in `pypeit_sensfunc` that was causing the script to crash because `par['fluxcalib']`
+  was not being passed to `sensfunc.SensFunc.get_instance()`.
diff --git a/pypeit/scripts/sensfunc.py b/pypeit/scripts/sensfunc.py
index bc4406711c..078500751b 100644
--- a/pypeit/scripts/sensfunc.py
+++ b/pypeit/scripts/sensfunc.py
@@ -142,7 +142,7 @@ def main(args):
             par = pypeitpar.PypeItPar.from_cfg_lines(cfg_lines=spectrograph_config_par.to_config(),
                 merge_with=(sensFile.cfg_lines,))
         else:
-            par = spectrograph_config_par 
+            par = pypeitpar.PypeItPar.from_cfg_lines(cfg_lines=spectrograph_config_par.to_config())
 
         # If algorithm was provided override defaults. Note this does undo .sens
         # file since they cannot both be passed
@@ -179,7 +179,7 @@ def main(args):
                         if args.outfile is None else args.outfile
         # Instantiate the relevant class for the requested algorithm
         sensobj = sensfunc.SensFunc.get_instance(args.spec1dfile, outfile, par['sensfunc'],
-                                                 debug=args.debug,
+                                                 par_fluxcalib=par['fluxcalib'], debug=args.debug,
                                                  chk_version=par['rdx']['chk_version'])
         # Generate the sensfunc
         sensobj.run()