diff --git a/conan/api/subapi/local.py b/conan/api/subapi/local.py
index dbcc4ead3b0..fd597897db0 100644
--- a/conan/api/subapi/local.py
+++ b/conan/api/subapi/local.py
@@ -102,7 +102,7 @@ def editable_list(self):
         return self._helpers.editable_packages.edited_refs
 
     def source(self, path, name=None, version=None, user=None, channel=None,
-               remotes: List[Remote] = None):
+               remotes: List[Remote] = None, lockfile=None):
         """ Calls the ``source()`` method of the current (user folder) ``conanfile.py``
 
         This method does not require computing a dependency graph, because the ``source()``
@@ -114,10 +114,11 @@ def source(self, path, name=None, version=None, user=None, channel=None,
         :param user: The user of the package. If not defined, it is taken from conanfile
         :param channel: The channel of the package. If not defined, it is taken from conanfile
         :param remotes: The remotes to resolve possible ``python-requires`` for this recipe if needed.
+        :param lockfile: The lockfile to use for the ``python-requires`` resolution, if needed.
         """
         loader = self._helpers.loader
         conanfile = loader.load_consumer(path, name=name, version=version,
-                                         user=user, channel=channel, graph_lock=None,
+                                         user=user, channel=channel, graph_lock=lockfile,
                                          remotes=remotes)
         # This profile is empty, but with the conf from global.conf
         profile = self._conan_api.profiles.get_profile([])
diff --git a/conan/cli/commands/source.py b/conan/cli/commands/source.py
index 4a694964b74..61dfdd6dca1 100644
--- a/conan/cli/commands/source.py
+++ b/conan/cli/commands/source.py
@@ -1,6 +1,6 @@
 import os
 
-from conan.cli.command import conan_command
+from conan.cli.command import conan_command, OnceArgument
 from conan.cli.args import add_reference_args
 
 
@@ -12,12 +12,20 @@ def source(conan_api, parser, *args):
     parser.add_argument("path", help="Path to a folder containing a conanfile.py. "
                                      "Defaults to current directory",
                         default=".", nargs="?")
+    parser.add_argument("-l", "--lockfile", action=OnceArgument,
+                        help="Path to a lockfile for python-requires resolution. Use "
+                             "--lockfile=\"\" to avoid automatic use of existing 'conan.lock' file")
+    parser.add_argument("--lockfile-partial", action="store_true",
+                        help="Do not raise an error if some dependency is not found in lockfile")
     add_reference_args(parser)
     args = parser.parse_args(*args)
 
     cwd = os.getcwd()
     path = conan_api.local.get_conanfile_path(args.path, cwd, py=True)
     enabled_remotes = conan_api.remotes.list()  # for python_requires not local
-    # TODO: Missing lockfile for python_requires
+    lockfile = conan_api.lockfile.get_lockfile(lockfile=args.lockfile,
+                                               conanfile_path=path,
+                                               cwd=cwd,
+                                               partial=args.lockfile_partial)
     conan_api.local.source(path, name=args.name, version=args.version, user=args.user,
-                           channel=args.channel, remotes=enabled_remotes)
+                           channel=args.channel, remotes=enabled_remotes, lockfile=lockfile)
diff --git a/test/integration/lockfile/test_lock_pyrequires.py b/test/integration/lockfile/test_lock_pyrequires.py
index cf1ba0d698b..2f5b46c4f97 100644
--- a/test/integration/lockfile/test_lock_pyrequires.py
+++ b/test/integration/lockfile/test_lock_pyrequires.py
@@ -40,6 +40,39 @@ class MyConanfileBase(ConanFile):
     assert "dep/0.1" not in client.out
 
 
+def test_source_should_respect_lockfile_pyrequires():
+    # "conan source" currently does not resolve python_requires against a lockfile the same way
+    # "install"/"create"/"export"/"build" do
+    client = TestClient(light=True)
+    consumer = textwrap.dedent("""
+        from conan import ConanFile
+        class Consumer(ConanFile):
+            python_requires = "dep/[>0.0]@user/channel"
+            def source(self):
+                v = self.python_requires["dep"].ref.version
+                self.output.info("SOURCE DEP VERSION: {}".format(v))
+        """)
+    client.save({"dep/conanfile.py": GenConanfile(),
+                 "conanfile.py": consumer})
+
+    client.run("export dep --name=dep --version=0.1 --user=user --channel=channel")
+    client.run("lock create conanfile.py")  # writes conan.lock, locks dep/0.1
+    lockfile = os.path.join(client.current_folder, "conan.lock")
+    assert os.path.isfile(lockfile)  # the lock is indeed present when "source" runs below
+
+    client.run("export dep --name=dep --version=0.2 --user=user --channel=channel")
+
+    # "install" auto-discovers "conan.lock" and correctly keeps resolving dep/0.1
+    client.run("install conanfile.py")
+    assert "dep/0.1@user/channel" in client.out
+    assert "dep/0.2" not in client.out
+
+    # "source" should behave the same way and also resolve the locked dep/0.1
+    client.run("source conanfile.py")
+    # This fails, it currently resolves to dep/0.2
+    assert "SOURCE DEP VERSION: 0.1" in client.out
+
+
 def test_transitive_matching_ranges():
     client = TestClient(light=True)
     tool = textwrap.dedent("""