diff --git a/.github/workflows/ci_workflows.yml b/.github/workflows/ci_workflows.yml
index 35e9fdc..9245a2c 100644
--- a/.github/workflows/ci_workflows.yml
+++ b/.github/workflows/ci_workflows.yml
@@ -44,7 +44,7 @@ jobs:
       with:
         fetch-depth: 0
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.x'
     - name: Lint with flake8
@@ -70,9 +70,9 @@ jobs:
       with:
         fetch-depth: 0
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
-        python-version: '3.8'
+        python-version: '3.11'
     - name: Install and build
       run: |
         python -m pip install --upgrade pip setuptools wheel
@@ -89,7 +89,7 @@ jobs:
       with:
         fetch-depth: 0
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.x'
     - name: Install and build
@@ -109,7 +109,7 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.x'
     - name: Install and build
diff --git a/.github/workflows/predeps_workflow.yml b/.github/workflows/predeps_workflow.yml
index 6ba514a..5310a99 100644
--- a/.github/workflows/predeps_workflow.yml
+++ b/.github/workflows/predeps_workflow.yml
@@ -23,7 +23,7 @@ jobs:
       with:
         fetch-depth: 0
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.11'
     - name: Install and build
diff --git a/.github/workflows/publish-to-pypi.yml b/.github/workflows/publish-to-pypi.yml
index 7a37ec6..1733e7c 100644
--- a/.github/workflows/publish-to-pypi.yml
+++ b/.github/workflows/publish-to-pypi.yml
@@ -25,7 +25,7 @@ jobs:
       with:
         fetch-depth: 0
 
-    - uses: actions/setup-python@v4
+    - uses: actions/setup-python@v5
       with:
         python-version: '3.x'
 
diff --git a/CHANGES.rst b/CHANGES.rst
index 67083c0..23cd420 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,15 @@
 1.5 (unreleased)
 ----------------
 
+Other Changes and Additions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- Compatibility with Ginga 5. [#234]
+
+- This version requires Python 3.9 or later.
+  Also bumped minimum versions of other dependencies to
+  ``astropy>=5``, ``ginga>=4.1``, and ``scipy>=1``. [#234]
+
 1.4 (2023-11-28)
 ----------------
 
diff --git a/docs/stginga/install.rst b/docs/stginga/install.rst
index 8bf95a3..b6c7635 100644
--- a/docs/stginga/install.rst
+++ b/docs/stginga/install.rst
@@ -5,7 +5,7 @@ Installation
 
 ``stginga`` requires:
 
-* Python 3.8 or later
+* Python 3.9 or later
 * Astropy
 * SciPy
 * Ginga, see `Ginga's documentation <https://ginga.readthedocs.io/>`_
diff --git a/setup.cfg b/setup.cfg
index fbe3aca..5dc0a46 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,10 +35,10 @@ packages = find:
 zip_safe = False
 install_requires =
     numpy
-    astropy>=3
-    ginga>=2.7
-    scipy>=0.18
-python_requires = >=3.8
+    astropy>=5
+    ginga>=4.1
+    scipy>=1
+python_requires = >=3.9
 
 [options.extras_require]
 test =
diff --git a/stginga/plugins/local_plugin_mixin.py b/stginga/plugins/local_plugin_mixin.py
index a5aabc9..b3aaaad 100644
--- a/stginga/plugins/local_plugin_mixin.py
+++ b/stginga/plugins/local_plugin_mixin.py
@@ -26,20 +26,14 @@
 class HelpMixin(object):
     def help(self):
         """Display online help for the plugin."""
-        if not self.fv.gpmon.has_plugin('WBrowser'):
-            self._help_docstring()
+        if not hasattr(self.fv, 'help_plugin'):
+            # ginga < v5.x, open in external browser
+            import webbrowser
+            webbrowser.open(self.help_url)
             return
 
-        self.fv.start_global_plugin('WBrowser')
-
-        # need to let GUI finish processing, it seems
-        self.fv.update_pending()
-
-        obj = self.fv.gpmon.get_plugin('WBrowser')
-
-        # Unlike Ginga, we do not attempt to download offline doc
-        # but just point to online doc directly.
-        obj.browse(self.help_url)
+        # ginga v5.x
+        self.fv.help_plugin(self, url=self.help_url)
 
 
 class MEFMixin(object):