diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 71e508f8..e17374fe 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -26,6 +26,9 @@ jobs:
       with:
         python-version: '3.10'
 
+    - name: Ensure latest pip
+      run: python -m pip install --upgrade pip
+
     - name: Install tox
       run: python -m pip install --upgrade tox
 
@@ -128,9 +131,20 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Ensure latest pip
+        run: python -m pip install --upgrade pip
+
       - name: Install tox
         run: python -m pip install --upgrade tox
 
+      - name: Cache tox virtual environment
+        uses: actions/cache@v3
+        with:
+          path: .tox
+          key: ${{ matrix.os }}-tox-${{ matrix.python-version }}-${{ hashFiles('pyproject.toml', 'tox.ini') }}
+          restore-keys: |
+            ${{ matrix.os }}-tox-${{ matrix.python-version }}-
+
       - name: Run unit tests
         if: ${{ ! matrix.tox-env && matrix.with-coverage }}
         run: tox -e py${{ matrix.python-version }}-cov -- testing/test_unit.py
@@ -196,9 +210,20 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Ensure latest pip
+        run: python -m pip install --upgrade pip
+
       - name: Install tox
         run: python -m pip install --upgrade tox
 
+      - name: Cache tox virtual environment
+        uses: actions/cache@v3
+        with:
+          path: .tox
+          key: ubuntu-latest-tox-${{ matrix.python-version }}-${{ hashFiles('pyproject.toml', 'tox.ini') }}
+          restore-keys: |
+            ubuntu-latest-tox-${{ matrix.python-version }}-
+
       - name: Run integration tests
         if: ${{ ! matrix.tox-env && matrix.with-coverage }}
         run: tox -e ${{ matrix.python-version }}-cov -- testing/test_integration.py
diff --git a/src/pytest_html/basereport.py b/src/pytest_html/basereport.py
index 8caa66bb..969a0fee 100644
--- a/src/pytest_html/basereport.py
+++ b/src/pytest_html/basereport.py
@@ -173,6 +173,7 @@ def pytest_sessionfinish(self, session):
             prefix=self._report.data["additionalSummary"]["prefix"],
             summary=self._report.data["additionalSummary"]["summary"],
             postfix=self._report.data["additionalSummary"]["postfix"],
+            session=session,
         )
         self._report.set_data("runningState", "Finished")
         self._generate_report()
diff --git a/src/pytest_html/hooks.py b/src/pytest_html/hooks.py
index f81f9e25..1d1b269d 100644
--- a/src/pytest_html/hooks.py
+++ b/src/pytest_html/hooks.py
@@ -7,7 +7,7 @@ def pytest_html_report_title(report):
     """Called before adding the title to the report"""
 
 
-def pytest_html_results_summary(prefix, summary, postfix):
+def pytest_html_results_summary(prefix, summary, postfix, session):
     """Called before adding the summary section to the report"""
 
 
diff --git a/testing/test_integration.py b/testing/test_integration.py
index a562e275..5b8bce12 100644
--- a/testing/test_integration.py
+++ b/testing/test_integration.py
@@ -8,7 +8,6 @@
 from base64 import b64encode
 from pathlib import Path
 
-import pkg_resources
 import pytest
 from assertpy import assert_that
 from bs4 import BeautifulSoup
@@ -28,12 +27,8 @@
 
 
 def run(pytester, path="report.html", cmd_flags=None, query_params=None):
-    if cmd_flags is None:
-        cmd_flags = []
-
-    if query_params is None:
-        query_params = {}
-    query_params = urllib.parse.urlencode(query_params)
+    cmd_flags = cmd_flags or []
+    query_params = urllib.parse.urlencode(query_params) if query_params else {}
 
     path = pytester.path.joinpath(path)
     pytester.runpytest("--html", path, *cmd_flags)
@@ -120,6 +115,8 @@ def file_content():
         )
     except AttributeError:
         # Needed for python < 3.9
+        import pkg_resources
+
         return pkg_resources.resource_string(
             "pytest_html", os.path.join("resources", "style.css")
         ).decode("utf-8")
diff --git a/testing/test_unit.py b/testing/test_unit.py
index 18ed204a..f60132e4 100644
--- a/testing/test_unit.py
+++ b/testing/test_unit.py
@@ -1,9 +1,10 @@
 pytest_plugins = ("pytester",)
 
 
-def run(pytester, path="report.html", *args):
+def run(pytester, path="report.html", cmd_flags=None):
+    cmd_flags = cmd_flags or []
     path = pytester.path.joinpath(path)
-    return pytester.runpytest("--html", path, *args)
+    return pytester.runpytest("--html", path, *cmd_flags)
 
 
 def test_duration_format_deprecation_warning(pytester):
@@ -19,8 +20,27 @@ def pytest_runtest_makereport(item, call):
     )
     pytester.makepyfile("def test_pass(): pass")
     result = run(pytester)
+    result.assert_outcomes(passed=1)
     result.stdout.fnmatch_lines(
         [
             "*DeprecationWarning: 'duration_formatter'*",
         ],
     )
+
+
+def test_html_results_summary_hook(pytester):
+    pytester.makeconftest(
+        """
+        import pytest
+
+        def pytest_html_results_summary(prefix, summary, postfix, session):
+            print(prefix)
+            print(summary)
+            print(postfix)
+            print(session)
+    """
+    )
+
+    pytester.makepyfile("def test_pass(): pass")
+    result = run(pytester)
+    result.assert_outcomes(passed=1)