diff --git a/opensafely/pull.py b/opensafely/pull.py
index 2e80b52..d3c28e4 100644
--- a/opensafely/pull.py
+++ b/opensafely/pull.py
@@ -1,6 +1,6 @@
+import argparse
 import subprocess
 import sys
-from collections import defaultdict
 from http.cookiejar import split_header_words
 from pathlib import Path
 from urllib.parse import urlparse
@@ -18,18 +18,29 @@
 # The deprecated `databuilder` name is still supported by job-runner, but we don't want
 # it showing up here
 IMAGES = list(config.ALLOWED_IMAGES - {"databuilder"})
-FULL_IMAGES = {f"{REGISTRY}/{image}" for image in IMAGES}
 DEPRECATED_REGISTRIES = ["docker.opensafely.org", "ghcr.io/opensafely"]
 IMAGES.sort()  # this is just for consistency for testing
 
 
+def valid_image(image_string):
+    if image_string == "all":
+        return image_string
+
+    name, _, _ = image_string.partition(":")
+    if name not in IMAGES:
+        raise argparse.ArgumentTypeError(
+            f"{image_string} is not a valid OpenSAFELY image: {','.join(IMAGES)}"
+        )
+
+    return image_string
+
+
 def add_arguments(parser):
-    choices = ["all"] + IMAGES
     parser.add_argument(
         "image",
         nargs="?",
-        choices=choices,
         help="OpenSAFELY docker image to update (default: all)",
+        type=valid_image,
         default="all",
     )
     parser.add_argument(
@@ -47,26 +58,36 @@ def main(image="all", force=False, project=None):
     if not docker_preflight_check():
         return False
 
+    local_images = get_local_images()
+
     if project:
         force = True
         images = get_actions_from_project_file(project)
     elif image == "all":
-        images = IMAGES
+        if force:
+            images = {
+                f"{name}:{get_default_version_for_image(name)}": None for name in IMAGES
+            }
+        else:
+            images = list(local_images)
     else:
         # if user has requested a specific image, pull it regardless
         force = True
         images = [image]
 
-    local_images = get_local_images()
     try:
         updated = False
         for image in images:
-            tag = f"{REGISTRY}/{image}"
-            if force or tag in local_images:
+            if force or image in local_images:
+                name, _, tag = image.partition(":")
+                if not tag:
+                    tag = get_default_version_for_image(name)
                 updated = True
-                print(f"Updating OpenSAFELY {image} image")
-                version = get_default_version_for_image(image)
-                subprocess.run(["docker", "pull", tag + f":{version}"], check=True)
+
+                print(f"Updating OpenSAFELY {name}:{tag} image")
+                subprocess.run(
+                    ["docker", "pull", f"{REGISTRY}/{name}:{tag}"], check=True
+                )
 
         if updated:
             remove_deprecated_images(local_images)
@@ -88,7 +109,7 @@ def get_actions_from_project_file(project_yaml):
 
     for name, action in project.actions.items():
         if action.run.name in IMAGES and action.run.name not in images:
-            images.append(action.run.name)
+            images.append(f"{action.run.name}:{action.run.version}")
 
     if not images:
         raise RuntimeError(f"No actions found in {project_yaml}")
@@ -106,19 +127,21 @@ def get_local_images():
             "--filter",
             "label=org.opensafely.action",
             "--no-trunc",
-            "--format={{.Repository}}={{.ID}}",
+            "--format={{.Repository}}:{{.Tag}}={{.ID}}",
         ],
         check=True,
         text=True,
         capture_output=True,
     )
-    images = defaultdict(list)
+    images = dict()
     for line in ps.stdout.splitlines():
         if not line.strip():
             continue
 
-        name, sha = line.split("=", 1)
-        images[name].append(sha)
+        line = line.replace("ghcr.io/opensafely-core/", "")
+
+        image, sha = line.split("=", 1)
+        images[image] = sha
 
     return images
 
@@ -135,6 +158,8 @@ def remove_deprecated_images(local_images):
 def get_default_version_for_image(name):
     if name in ["ehrql"]:
         return "v1"
+    elif name == "python":
+        return "v2"
     else:
         return "latest"
 
@@ -143,22 +168,34 @@ def get_default_version_for_image(name):
 token = None
 
 
-def get_remote_sha(full_name, tag):
+def dockerhub_api(path):
     """Get the current sha for a tag from a docker registry."""
     global token
 
-    parsed = urlparse("https://" + full_name)
-    manifest_url = f"https://ghcr.io/v2/{parsed.path}/manifests/{tag}"
+    url = f"https://ghcr.io/{path}"
 
+    # Docker API requires auth token, even for public resources.
+    # However, we can reuse a public token.
     if token is None:
-        # Docker API requires auth token, even for public resources.
-        # However, we can reuse a public token.
-        response = session.get(manifest_url)
+        response = session.get(url)
+        token = get_auth_token(response.headers["www-authenticate"])
+    else:
+        response = session.get(url, headers={"Authorization": f"Bearer {token}"})
+
+    # refresh token if needed
+    if response.status_code == 401:
         token = get_auth_token(response.headers["www-authenticate"])
+        response = session.get(url, headers={"Authorization": f"Bearer {token}"})
 
-    response = session.get(manifest_url, headers={"Authorization": f"Bearer {token}"})
     response.raise_for_status()
-    return response.json()["config"]["digest"]
+    return response.json()
+
+
+def get_remote_sha(full_name, tag):
+    """Get the current sha for a tag from a docker registry."""
+    parsed = urlparse("https://" + full_name)
+    response = dockerhub_api(f"/v2/{parsed.path}/manifests/{tag}")
+    return response["config"]["digest"]
 
 
 def get_auth_token(header):
@@ -179,14 +216,11 @@ def check_version():
     need_update = []
     local_images = get_local_images()
 
-    for image in IMAGES:
-        full_name = f"{REGISTRY}/{image}"
-        local_shas = local_images.get(full_name, [])
-        if local_shas:
-            version = get_default_version_for_image(image)
-            latest_sha = get_remote_sha(full_name, version)
-            if latest_sha not in local_shas:
-                need_update.append(image)
+    for image, local_sha in local_images.items():
+        name, _, tag = image.partition(":")
+        latest_sha = get_remote_sha(f"{REGISTRY}/{name}", tag)
+        if latest_sha != local_sha:
+            need_update.append(image)
 
     if need_update:
         print(
diff --git a/tests/conftest.py b/tests/conftest.py
index 0776733..ddea745 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -143,7 +143,7 @@ def run(monkeypatch):
     monkeypatch.setattr(subprocess, "run", fixture.run)
     yield fixture
     if len(fixture) != 0:
-        remaining = "\n".join(str(cmd) for cmd, _ in fixture)
+        remaining = "\n".join(str(f[0]) for f in fixture if f)
         raise AssertionError(
             f"run fixture had unused remaining expected cmds:\n{remaining}"
         )
diff --git a/tests/test_pull.py b/tests/test_pull.py
index b17625b..3447766 100644
--- a/tests/test_pull.py
+++ b/tests/test_pull.py
@@ -22,7 +22,7 @@ def expect_local_images(run, stdout="", **kwargs):
             "--filter",
             "label=org.opensafely.action",
             "--no-trunc",
-            "--format={{.Repository}}={{.ID}}",
+            "--format={{.Repository}}:{{.Tag}}={{.ID}}",
         ],
         stdout=stdout,
         **kwargs,
@@ -45,7 +45,7 @@ def test_default_no_local_images_force(run, capsys):
     run.expect(["docker", "pull", tag("cohortextractor")])
     run.expect(["docker", "pull", tag("ehrql", version="v1")])
     run.expect(["docker", "pull", tag("jupyter")])
-    run.expect(["docker", "pull", tag("python")])
+    run.expect(["docker", "pull", tag("python", version="v2")])
     run.expect(["docker", "pull", tag("r")])
     run.expect(["docker", "pull", tag("sqlrunner")])
     run.expect(["docker", "pull", tag("stata-mp")])
@@ -64,20 +64,20 @@ def test_default_no_local_images_force(run, capsys):
     out, err = capsys.readouterr()
     assert err == ""
     assert out.splitlines() == [
-        "Updating OpenSAFELY cohortextractor image",
-        "Updating OpenSAFELY ehrql image",
-        "Updating OpenSAFELY jupyter image",
-        "Updating OpenSAFELY python image",
-        "Updating OpenSAFELY r image",
-        "Updating OpenSAFELY sqlrunner image",
-        "Updating OpenSAFELY stata-mp image",
+        "Updating OpenSAFELY cohortextractor:latest image",
+        "Updating OpenSAFELY ehrql:v1 image",
+        "Updating OpenSAFELY jupyter:latest image",
+        "Updating OpenSAFELY python:v2 image",
+        "Updating OpenSAFELY r:latest image",
+        "Updating OpenSAFELY sqlrunner:latest image",
+        "Updating OpenSAFELY stata-mp:latest image",
         "Pruning old OpenSAFELY docker images...",
     ]
 
 
 def test_default_with_local_images(run, capsys):
     run.expect(["docker", "info"])
-    expect_local_images(run, stdout="ghcr.io/opensafely-core/r=sha")
+    expect_local_images(run, stdout="ghcr.io/opensafely-core/r:latest=sha")
     run.expect(["docker", "pull", tag("r")])
     run.expect(
         [
@@ -94,7 +94,7 @@ def test_default_with_local_images(run, capsys):
     out, err = capsys.readouterr()
     assert err == ""
     assert out.splitlines() == [
-        "Updating OpenSAFELY r image",
+        "Updating OpenSAFELY r:latest image",
         "Pruning old OpenSAFELY docker images...",
     ]
 
@@ -118,7 +118,7 @@ def test_specific_image(run, capsys):
     out, err = capsys.readouterr()
     assert err == ""
     assert out.splitlines() == [
-        "Updating OpenSAFELY r image",
+        "Updating OpenSAFELY r:latest image",
         "Pruning old OpenSAFELY docker images...",
     ]
 
@@ -144,9 +144,9 @@ def test_project(run, capsys):
     out, err = capsys.readouterr()
     assert err == ""
     assert out.splitlines() == [
-        "Updating OpenSAFELY cohortextractor image",
-        "Updating OpenSAFELY python image",
-        "Updating OpenSAFELY jupyter image",
+        "Updating OpenSAFELY cohortextractor:latest image",
+        "Updating OpenSAFELY python:latest image",
+        "Updating OpenSAFELY jupyter:latest image",
         "Pruning old OpenSAFELY docker images...",
     ]
 
@@ -169,14 +169,14 @@ def test_remove_deprecated_images(run):
 def test_check_version_out_of_date(run, capsys):
     expect_local_images(
         run,
-        stdout="ghcr.io/opensafely-core/python=sha256:oldsha",
+        stdout="ghcr.io/opensafely-core/python:latest=sha256:oldsha",
     )
 
     assert len(pull.check_version()) == 1
     out, err = capsys.readouterr()
     assert out == ""
     assert err.splitlines() == [
-        "Warning: the OpenSAFELY docker images for python actions are out of date - please update by running:",
+        "Warning: the OpenSAFELY docker images for python:latest actions are out of date - please update by running:",
         "    opensafely pull",
         "",
     ]
@@ -185,28 +185,9 @@ def test_check_version_out_of_date(run, capsys):
 def test_check_version_up_to_date(run, capsys):
     current_sha = pull.get_remote_sha("ghcr.io/opensafely-core/python", "latest")
     pull.token = None
-
-    expect_local_images(
-        run,
-        stdout=f"ghcr.io/opensafely-core/python={current_sha}",
-    )
-
-    assert len(pull.check_version()) == 0
-    out, err = capsys.readouterr()
-    assert err == ""
-    assert out.splitlines() == []
-
-
-def test_check_version_up_to_date_old_sha(run, capsys):
-    current_sha = pull.get_remote_sha("ghcr.io/opensafely-core/python", "latest")
-    pull.token = None
-
     expect_local_images(
         run,
-        stdout=(
-            f"ghcr.io/opensafely-core/python={current_sha}\n"
-            f"ghcr.io/opensafely-core/python=oldsha"
-        ),
+        stdout=f"ghcr.io/opensafely-core/python:latest={current_sha}",
     )
 
     assert len(pull.check_version()) == 0