diff --git a/ChangeLog b/ChangeLog
index d5d8a334..bc02ee54 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+*setools-4.5.1 (01 May 2024)
+
+  * Correct annotations of NetworkX types to make it optional again.
+  * Fix packaging issue for apol's style sheet (apol.css).
+
 *setools-4.5.0 (21 Mar 2024)
 
   * Rework apol to fully generate the UI programmatically.
diff --git a/setools/dta.py b/setools/dta.py
index 5ce50f44..2232b91a 100644
--- a/setools/dta.py
+++ b/setools/dta.py
@@ -282,7 +282,7 @@ def results(self) -> Iterable[DTAPath] | Iterable[DomainTransition]:
                 case _:
                     raise ValueError(f"Unknown analysis mode: {self.mode}")
 
-    def graphical_results(self) -> nx.DiGraph:
+    def graphical_results(self) -> "nx.DiGraph":
 
         """
         Return the results of the analysis as a NetworkX directed graph.
@@ -846,7 +846,7 @@ class Edge(NetworkXGraphEdge):
                 The default is False.
     """
 
-    G: nx.DiGraph
+    G: "nx.DiGraph"
     source: Type
     target: Type
     create: InitVar[bool] = False
diff --git a/setools/infoflow.py b/setools/infoflow.py
index 0d48bbed..a3500269 100644
--- a/setools/infoflow.py
+++ b/setools/infoflow.py
@@ -207,7 +207,7 @@ def results(self) -> Iterable[InfoFlowPath] | Iterable["InfoFlowStep"]:
                 case _:
                     raise ValueError(f"Unknown analysis mode: {self.mode}")
 
-    def graphical_results(self) -> nx.DiGraph:
+    def graphical_results(self) -> "nx.DiGraph":
 
         """
         Return the results of the analysis as a NetworkX directed graph.
@@ -590,7 +590,7 @@ class InfoFlowStep(NetworkXGraphEdge):
                 The default is False.
     """
 
-    G: nx.DiGraph
+    G: "nx.DiGraph"
     source: Type
     target: Type
     create: InitVar[bool] = False
diff --git a/setup.py b/setup.py
index a18c523d..b2245ac7 100644
--- a/setup.py
+++ b/setup.py
@@ -65,7 +65,7 @@
         installed_data.append((join('share/man', lang, 'man1'), glob.glob(join("man", lang, "*.1"))))
 
 setup(name='setools',
-      version='4.5.0',
+      version='4.5.1',
       description='SELinux policy analysis tools.',
       author='Chris PeBenito',
       author_email='pebenito@ieee.org',
@@ -75,7 +75,7 @@
                 'setoolsgui.widgets.models', 'setoolsgui.widgets.views'],
       scripts=['apol', 'sediff', 'seinfo', 'seinfoflow', 'sesearch', 'sedta', 'sechecker'],
       data_files=installed_data,
-      package_data={'': ['*.html'],
+      package_data={'': ['*.css', '*.html'],
                     'setools': ['perm_map', 'policyrep.pyi', 'py.typed']},
       ext_modules=cythonize(ext_py_mods, include_path=['setools/policyrep'],
                             annotate=cython_annotate,
diff --git a/tox.ini b/tox.ini
index 551ce15c..d69225ea 100644
--- a/tox.ini
+++ b/tox.ini
@@ -41,7 +41,9 @@ commands        = mypy -p setools -p setoolsgui -p tests -p tests-gui
 
 [testenv:install]
 deps            = {[testenv]deps}
-commands        = {envpython} -m pip install --use-pep517 .
+allowlist_externals = find
+commands        = {envpython} -m pip install --use-pep517 --root {envtmpdir}/setools .
+                  find {envtmpdir}/setools
 
 [testenv]
 passenv         = USERSPACE_SRC