diff --git a/providers/standard/src/airflow/providers/standard/operators/python.py b/providers/standard/src/airflow/providers/standard/operators/python.py
index 3d8902dcfc0d1..37aa79c33433e 100644
--- a/providers/standard/src/airflow/providers/standard/operators/python.py
+++ b/providers/standard/src/airflow/providers/standard/operators/python.py
@@ -21,6 +21,7 @@
 import json
 import logging
 import os
+import re
 import shutil
 import subprocess
 import sys
@@ -35,6 +36,9 @@
 from typing import TYPE_CHECKING, Any, Callable, NamedTuple, cast
 
 import lazy_object_proxy
+from packaging.requirements import InvalidRequirement, Requirement
+from packaging.specifiers import InvalidSpecifier
+from packaging.version import InvalidVersion
 
 from airflow.exceptions import (
     AirflowConfigException,
@@ -848,10 +852,38 @@ def execute_callable(self):
 
     def _iter_serializable_context_keys(self):
         yield from self.BASE_SERIALIZABLE_CONTEXT_KEYS
-        if self.system_site_packages or "apache-airflow" in self.requirements:
+
+        found_airflow = found_pendulum = False
+
+        if self.system_site_packages:
+            # If we're using system packages, assume both are present
+            found_airflow = found_pendulum = True
+        else:
+            for raw_str in self.requirements:
+                line = raw_str.strip()
+                # Skip blank lines and full‐line comments
+                if not line or line.startswith("#"):
+                    continue
+
+                # Strip off any inline comment
+                # e.g. turn "foo==1.2.3  # comment" → "foo==1.2.3"
+                req_str = re.sub(r"#.*$", "", line).strip()
+
+                try:
+                    req = Requirement(req_str)
+                except (InvalidRequirement, InvalidSpecifier, InvalidVersion) as e:
+                    raise ValueError(f"Invalid requirement '{raw_str}': {e}") from e
+
+                if req.name == "apache-airflow":
+                    found_airflow = found_pendulum = True
+                    break
+                elif req.name == "pendulum":
+                    found_pendulum = True
+
+        if found_airflow:
             yield from self.AIRFLOW_SERIALIZABLE_CONTEXT_KEYS
             yield from self.PENDULUM_SERIALIZABLE_CONTEXT_KEYS
-        elif "pendulum" in self.requirements:
+        elif found_pendulum:
             yield from self.PENDULUM_SERIALIZABLE_CONTEXT_KEYS
 
 
diff --git a/providers/standard/tests/unit/standard/operators/test_python.py b/providers/standard/tests/unit/standard/operators/test_python.py
index d30938f4f00bf..e8a0091481647 100644
--- a/providers/standard/tests/unit/standard/operators/test_python.py
+++ b/providers/standard/tests/unit/standard/operators/test_python.py
@@ -1451,6 +1451,99 @@ def f(
 
         self.run_as_task(f, serializer=serializer, system_site_packages=False, requirements=None)
 
+    @pytest.mark.parametrize(
+        "requirements, system_site, want_airflow, want_pendulum",
+        [
+            # nothing → just base keys
+            ([], False, False, False),
+            # site-packages → base keys + pendulum keys
+            ([], True, True, True),
+            # apache-airflow / no version constraint
+            (["apache-airflow"], False, True, True),
+            # specific version
+            (["apache-airflow==2.10.2"], False, True, True),
+            # minimum version
+            (["apache-airflow>=2.10"], False, True, True),
+            # pendulum / no version constraint
+            (["pendulum"], False, False, True),
+            # compatible release
+            (["pendulum~=2.1.0"], False, False, True),
+            # other package
+            (["foo==1.0.0"], False, False, False),
+            # with other package
+            (["apache-airflow", "foo"], False, True, True),
+            # full-line comment only
+            (["# comment"], False, False, False),
+            # inline comment after requirement
+            (["apache-airflow==2.10.2  # comment"], False, True, True),
+            # blank line + requirement
+            (["", "pendulum"], False, False, True),
+            # indented comment + requirement
+            (["  # comment", "pendulum~=2.1.0"], False, False, True),
+        ],
+    )
+    def test_iter_serializable_context_keys(self, requirements, system_site, want_airflow, want_pendulum):
+        def func():
+            return "test_return_value"
+
+        op = PythonVirtualenvOperator(
+            task_id="task",
+            python_callable=func,
+            requirements=requirements,
+            system_site_packages=system_site,
+        )
+        keys = set(op._iter_serializable_context_keys())
+
+        base_keys = set(op.BASE_SERIALIZABLE_CONTEXT_KEYS)
+        airflow_keys = set(op.AIRFLOW_SERIALIZABLE_CONTEXT_KEYS)
+        pendulum_keys = set(op.PENDULUM_SERIALIZABLE_CONTEXT_KEYS)
+
+        # BASE keys always present
+        assert base_keys <= keys
+
+        # AIRFLOW keys only when expected
+        if want_airflow:
+            assert airflow_keys <= keys, f"expected AIRFLOW keys for requirements: {requirements}"
+        else:
+            assert not (airflow_keys & keys), f"unexpected AIRFLOW keys for requirements: {requirements}"
+
+        # PENDULUM keys only when expected
+        if want_pendulum:
+            assert pendulum_keys <= keys, f"expected PENDULUM keys for requirements: {requirements}"
+        else:
+            assert not (pendulum_keys & keys), f"unexpected PENDULUM keys for requirements: {requirements}"
+
+    @pytest.mark.parametrize(
+        "invalid_requirement",
+        [
+            # invalid version format
+            "pendulum==3..0",
+            # invalid operator (=< instead of <=)
+            "apache-airflow=<2.0",
+            # same invalid operator on pendulum
+            "pendulum=<3.0",
+            # totally malformed
+            "invalid requirement",
+        ],
+    )
+    def test_iter_serializable_context_keys_invalid_requirement(self, invalid_requirement):
+        def func():
+            return "test_return_value"
+
+        op = PythonVirtualenvOperator(
+            task_id="task",
+            python_callable=func,
+            requirements=[invalid_requirement],
+            system_site_packages=False,
+        )
+
+        with pytest.raises(ValueError) as exc_info:
+            # Consume the generator to trigger parsing
+            list(op._iter_serializable_context_keys())
+
+        msg = str(exc_info.value)
+        assert f"Invalid requirement '{invalid_requirement}'" in msg
+
 
 # when venv tests are run in parallel to other test they create new processes and this might take
 # quite some time in shared docker environment and get some contention even between different containers