diff --git a/astroquery/utils/system_tools.py b/astroquery/utils/system_tools.py
index 220306bfea..09c98685bb 100644
--- a/astroquery/utils/system_tools.py
+++ b/astroquery/utils/system_tools.py
@@ -1,33 +1,6 @@
 # Licensed under a 3-clause BSD style license - see LICENSE.rst
 
-import gzip
 import os
-import shutil
-
-
-def gunzip(filename):
-    """ Decompress a file with gzip.
-
-    Parameters
-    ----------
-    filename : str
-        Fully qualified path of the file to decompress.
-
-    Returns
-    -------
-    filename : str
-        Name of the decompressed file (or input filename if gzip is not
-        available).
-    """
-
-    # ".fz" denotes RICE rather than gzip compression
-    if not filename.endswith('.fz'):
-        with gzip.open(filename, 'rb') as f_in:
-            with open(filename.rsplit(".", 1)[0], 'wb') as f_out:
-                shutil.copyfileobj(f_in, f_out)
-        return filename.rsplit(".", 1)[0]
-    else:
-        return filename
 
 
 # If there is an update issue of astropy#2793 that got merged, this should
diff --git a/astroquery/utils/tests/test_system_tools.py b/astroquery/utils/tests/test_system_tools.py
deleted file mode 100644
index 32e98d6e58..0000000000
--- a/astroquery/utils/tests/test_system_tools.py
+++ /dev/null
@@ -1,18 +0,0 @@
-# Licensed under a 3-clause BSD style license - see LICENSE.rst
-
-import gzip
-
-from ..system_tools import gunzip
-
-
-def test_gunzip(tmp_path):
-    filename = tmp_path / 'test_gunzip.txt.gz'
-    # First create a gzip file
-    content = b"Bla"
-    with gzip.open(filename, "wb") as f:
-        f.write(content)
-    # Then test our gunzip command works
-    gunzip(str(filename))
-    with open(filename.with_suffix(''), "rb") as f:
-        new_content = f.read()
-    assert new_content == content