diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 08eebc6..6fe659a 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -27,8 +27,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: ["ubuntu-latest", "macos-latest", "windows-latest"]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        os: ["ubuntu-latest", "macos-latest"]
+        python-version: ["3.10", "3.11", "3.12"]
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python
@@ -40,10 +40,6 @@ jobs:
           pip install --upgrade virtualenv
           pip install --upgrade pip setuptools
           virtualenv --upgrade-embed-wheels
-          pip install numpy
-          pip show numpy
-          pip install cgatcore
-          pip install cgat
           pip install -e .[tests]
       - name: Test with pytest
         run: |
diff --git a/isoslam/all_introns_counts_and_info.py b/isoslam/all_introns_counts_and_info.py
index 091a740..db61f31 100644
--- a/isoslam/all_introns_counts_and_info.py
+++ b/isoslam/all_introns_counts_and_info.py
@@ -12,14 +12,10 @@
 about it's event assignment, number of conversions, coverage etc.
 """
 
+from argparse import ArgumentParser
 import sys
-from collections import defaultdict
 
-import cgat.GTF as GTF
-import cgatcore.experiment as E
-import cgatcore.iotools as iotools
 import pandas as pd
-import pysam as pysam
 
 from isoslam import isoslam, io
 
@@ -31,9 +27,7 @@ def main(argv=None):
     if argv is None:
         argv = sys.argv
 
-    # setup command line parser
-    parser = E.ArgumentParser(description=__doc__)
-
+    parser = ArgumentParser(description=__doc__)
     parser.add_argument(
         "-b",
         "--bam",
@@ -41,15 +35,12 @@ def main(argv=None):
         type=str,
         help="Supply a path to the bam file that has undergone read assignment with featureCounts",
     )
-
     parser.add_argument(
         "-g", "--gtf", dest="gtf_path", type=str, help="Supply a path to the transcript assembly gtf file"
     )
-
     parser.add_argument(
         "-bed", dest="utron_bed", type=str, help="Supply a path to the utron bed file. Must be bed6 format"
     )
-
     parser.add_argument(
         "-o",
         "--out",
@@ -58,7 +49,6 @@ def main(argv=None):
         help="""Supply a path to the output file. This file will contain
                         conversions per pair, accounting for stranding""",
     )
-
     parser.add_argument("-vcf", "--vcf", dest="vcf_path", type=str, help="""Supply a path to the VCF.gz file""")
 
     argv_as_dictionary = vars(argv)
@@ -118,8 +108,6 @@ def fragment_iterator(read_iterator):
             i_progress += 1
 
             if i_progress == 10000:
-                # E.debug(str(i_total_progress) + " pairs processed")
-                # E.debug(str(i) + "spliced/retained pairs processed")
                 i_progress = 0
 
             read1_start = read1.reference_start
@@ -506,8 +494,6 @@ def fragment_iterator(read_iterator):
                 results = pd.concat([results, row])
 
     return results.sort_values(by=["read_uid", "transcript_id", "chr", "start", "end"])
-    # write footer and output benchmark information.
-    # E.stop()
 
 
 if __name__ == "__main__":
diff --git a/pyproject.toml b/pyproject.toml
index 1bf5778..a96b0e2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,8 +36,6 @@ keywords = [
 ]
 dependencies = [
   "apsw",
-  # "cgat",
-  # "cgatcore",
   "gevent",
   "loguru",
   "matplotlib",
@@ -45,7 +43,6 @@ dependencies = [
   "pandas",
   "pysam",
   "ruamel.yaml",
-  # "ruffus",
   "sqlalchemy",
 ]
 
@@ -57,6 +54,7 @@ tests = [
   "pytest-cov",
   "pytest-github-actions-annotate-failures",
   "pytest-mpl",
+  "pytest-regtest",
   "pytest-testmon",
   "syrupy",
 ]