diff --git a/README.rst b/README.rst
index 984d968..15310ff 100644
--- a/README.rst
+++ b/README.rst
@@ -185,6 +185,11 @@ put it directly into ``pip``.
 Version History
 ===============
 
+0.11.1
+  * Ability to run ``hashin --version`` to see what version of hashin is
+    installed.
+    See https://github.com/peterbe/hashin/issues/41
+
 0.11.0
   * Cope with leading zeros in version numbers when figuring out what
     the latest version is.
diff --git a/hashin.py b/hashin.py
index 6d05a41..3c9159c 100755
--- a/hashin.py
+++ b/hashin.py
@@ -64,6 +64,13 @@ parser.add_argument(
     action='append',
     default=[],
 )
+parser.add_argument(
+    '--version',
+    help='Version of hashin',
+    action='store_true',
+    default=False,
+)
+
 
 major_pip_version = int(pip.__version__.split('.')[0])
 if major_pip_version < 8:
@@ -408,6 +415,13 @@ def get_package_hashes(
 
 
 def main():
+    if '--version' in sys.argv[1:]:
+        # Can't be part of argparse because the 'packages' is mandatory
+        # print out the version of self
+        import pkg_resources
+        print(pkg_resources.get_distribution('hashin').version)
+        return 0
+
     args = parser.parse_args()
 
     return run(

hashin --version should say what version hashin is
Title says it all. 
diff --git a/tests/test_arg_parse.py b/tests/test_arg_parse.py
index e570635..cfdacdc 100644
--- a/tests/test_arg_parse.py
+++ b/tests/test_arg_parse.py
@@ -19,6 +19,7 @@ def test_everything():
         python_version=['3.5'],
         requirements_file='reqs.txt',
         verbose=True,
+        version=False,
     )
     eq_(args, (expected, []))
 
@@ -37,6 +38,7 @@ def test_everything_long():
         python_version=['3.5'],
         requirements_file='reqs.txt',
         verbose=True,
+        version=False,
     )
     eq_(args, (expected, []))
 
@@ -49,5 +51,6 @@ def test_minimal():
         python_version=[],
         requirements_file='requirements.txt',
         verbose=False,
+        version=False,
     )
     eq_(args, (expected, []))

pip install -e .
parse_log_pytest
pytest
nose mock pytest
3.9
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
exceptiongroup @ file:///croot/exceptiongroup_1706031385326/work
-e git+https://github.com/peterbe/hashin.git@469e16c992dd8952871254a64355335a72afe35c#egg=hashin
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
mock==5.2.0
nose==1.3.7
packaging @ file:///croot/packaging_1734472117206/work
pluggy @ file:///croot/pluggy_1733169602837/work
pytest @ file:///croot/pytest_1738938843180/work
tomli @ file:///opt/conda/conda-bld/tomli_1657175507142/work

name: hashin
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - exceptiongroup=1.2.0=py39h06a4308_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - packaging=24.2=py39h06a4308_0
  - pip=25.0=py39h06a4308_0
  - pluggy=1.5.0=py39h06a4308_0
  - pytest=8.3.4=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tomli=2.0.1=py39h06a4308_0
  - tzdata=2025a=h04d1e81_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - mock==5.2.0
      - nose==1.3.7
prefix: /opt/conda/envs/hashin

tests/test_arg_parse.py::test_everything tests/test_arg_parse.py::test_everything_long tests/test_arg_parse.py::test_minimal
README.rst hashin.py
README.rst hashin.py