diff --git a/setup.cfg b/setup.cfg
index 414b5a432cd89f0611c84c6d3b0a4d4bfd17f0e7..c7a8c29373ecc489309b8c90e04305a2841535fb 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -34,8 +34,10 @@ keywords =
 [options]
 packages = find:
 install_requires =
-    setuptools_scm
     hist
+    importlib_resources
+    prettytable
+    setuptools_scm
     uproot
 python_requires = >=3.6
 include_package_data = True
@@ -48,12 +50,10 @@ where = src
 [options.extras_require]
 all =
     black
-    importlib_resources
     ipykernel
     matplotlib
     numpydoc
     pillow
-    prettytable
     pytest
     pytest-cov
     pytest-flake8
@@ -67,12 +67,10 @@ all =
     wheel
 dev =
     black
-    importlib_resources
     ipykernel
     matplotlib
     numpydoc
     pillow
-    prettytable
     pytest
     pytest-cov
     pytest-flake8
diff --git a/src/km3irf/utils.py b/src/km3irf/utils.py
index dcfcc8771a5f0bbb32048d06d34795d5832dc411..bfda6c09025e977bd4ede0c424e471e17299e60f 100644
--- a/src/km3irf/utils.py
+++ b/src/km3irf/utils.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
-from calc import Calculator
+from .calc import Calculator
 from astropy.io import fits
 from os import path
 data_dir = path.join(path.dirname(__file__), 'data')
@@ -58,18 +58,9 @@ def merge_fits(aeff_fits=path.join(data_dir, "aeff.fits"),
     file_bkg = fits.open(bkg_fits)
     hdu_list.append(file_bkg[1])
     hdu_list[4].name = 'BACKGROUND'
-
     
     new_fits_file = fits.HDUList(hdu_list)
-    # new_fits_file.writeto(f'.data/{output_file}', overwrite=True)
-    # new_fits_file.writeto(output_file, overwrite=True)
     new_fits_file.writeto(path.join(data_dir, output_file), overwrite=True)
-    # new_fits_file.writeto(f'.data/{output_file}', overwrite=True)
-    # new_fits_file.close()
-
-    # with fits.open(path.join(data_dir, output_file), mode='update') as new_fits_file:
-    #     new_fits_file = fits.HDUList(hdu_list)
-    #     new_fits_file.writeto(path.join(data_dir, output_file), overwrite=True)
 
     file_aeff.close()
     file_psf.close()