diff --git a/GooseBib/bibtex.py b/GooseBib/bibtex.py
index 56b1484..65b4584 100644
--- a/GooseBib/bibtex.py
+++ b/GooseBib/bibtex.py
@@ -11,6 +11,7 @@
 import io
 import os
 import re
+import sys
 import textwrap
 import warnings
 from collections import defaultdict
@@ -1181,13 +1182,20 @@ def _split_lines(self, text, width):
     return parser
 
 
-def GbibClean():
+def _parse(parser: argparse.ArgumentParser, cli_args: list[str]) -> argparse.ArgumentParser:
+    if cli_args is None:
+        return parser.parse_args(sys.argv[1:])
+
+    return parser.parse_args([str(arg) for arg in cli_args])
+
+
+def GbibClean(cli_args: list[str] = None):
     """
     Command-line tool to clean a BibTeX database, see ``--help``.
     """
 
     parser = _GbibClean_parser()
-    args = parser.parse_args()
+    args = _parse(parser, cli_args)
     renamed = {}
     merged = {}
     is_unique = False
diff --git a/tests/test_GbibClean.py b/tests/test_GbibClean.py
index bfa10e0..75d4a71 100644
--- a/tests/test_GbibClean.py
+++ b/tests/test_GbibClean.py
@@ -7,6 +7,8 @@
 import bibtexparser
 import yaml
 
+import GooseBib as gbib
+
 dirname = os.path.dirname(__file__)
 
 
@@ -20,7 +22,7 @@ def test_inplace(self):
         output = os.path.join(dirname, "output.bib")
         shutil.copy2(source, output)
         data = os.path.join(dirname, "library.yaml")
-        subprocess.check_output(["GbibClean", "--in-place", output])
+        gbib.bibtex.GbibClean(["--in-place", output])
 
         with open(output) as file:
             bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())
@@ -43,7 +45,7 @@ def test_mendeley(self):
         source = os.path.join(dirname, "library_mendeley.bib")
         output = os.path.join(dirname, "output.bib")
         data = os.path.join(dirname, "library.yaml")
-        subprocess.check_output(["GbibClean", "-f", "-o", output, source])
+        gbib.bibtex.GbibClean(["-f", "-o", output, source])
 
         with open(output) as file:
             bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())
@@ -66,7 +68,7 @@ def test_hidden_doi_arxiv(self):
         source = os.path.join(dirname, "library_hidden_doi_arxiv.bib")
         output = os.path.join(dirname, "output.bib")
         data = os.path.join(dirname, "library.yaml")
-        subprocess.check_output(["GbibClean", "-f", "-o", output, source])
+        gbib.bibtex.GbibClean(["-f", "-o", output, source])
 
         with open(output) as file:
             bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())
@@ -143,7 +145,7 @@ def test_authorsep(self):
         source = os.path.join(dirname, "library_mendeley.bib")
         output = os.path.join(dirname, "output.bib")
         data = os.path.join(dirname, "library.yaml")
-        subprocess.check_output(["GbibClean", "-f", "--author-sep", " ", "-o", output, source])
+        gbib.bibtex.GbibClean(["-f", "--author-sep", " ", "-o", output, source])
 
         with open(output) as file:
             bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())
@@ -171,7 +173,7 @@ def test_authorsep(self):
     def test_no_title(self):
         source = os.path.join(dirname, "library_mendeley.bib")
         output = os.path.join(dirname, "output.bib")
-        subprocess.check_output(["GbibClean", "-f", "--no-title", "-o", output, source])
+        gbib.bibtex.GbibClean(["-f", "--no-title", "-o", output, source])
 
         with open(output) as file:
             bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())
@@ -204,7 +206,7 @@ def test_journalrename(self):
             source = os.path.join(dirname, "library_mendeley.bib")
             output = os.path.join(dirname, "output.bib")
             data = os.path.join(dirname, "library.yaml")
-            subprocess.check_output(["GbibClean", "-f", "-j", key, "-o", output, source])
+            gbib.bibtex.GbibClean(["-f", "-j", key, "-o", output, source])
 
             with open(output) as file:
                 bib = bibtexparser.load(file, parser=bibtexparser.bparser.BibTexParser())