diff --git a/docs/cpuif/customizing.rst b/docs/cpuif/customizing.rst
index dc806c5..5ceea58 100644
--- a/docs/cpuif/customizing.rst
+++ b/docs/cpuif/customizing.rst
@@ -93,7 +93,8 @@ The easiest way to add your cpuif is via the TOML config file. See the
 Via a package's entry point definition
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 If you are publishing a collection of PeakRDL plugins as an installable Python
-package, you can advertise them to PeakRDL using an entry point.
+package, you can advertise them to PeakRDL using an entry point defined in your
+``pyproject.toml`` file.
 This advertises your custom CPUIF class to the PeakRDL-regblock tool as a plugin
 that should be loaded, and made available as a command-line option in PeakRDL.
 
@@ -103,12 +104,11 @@ that should be loaded, and made available as a command-line option in PeakRDL.
     my-cpuif = "my_package.my_module:MyCPUIF"
 
 
-*   ``my_package``: The name of your installable Python module
 *   ``peakrdl-regblock.cpuif``: This is the namespace that PeakRDL-regblock will
     search. Any cpuif plugins you create must be enclosed in this namespace in
     order to be discovered.
-*   ``my_package.my_module:MyCPUIF``: This is the import path that
-    points to your CPUIF class definition.
 *   ``my-cpuif``: The lefthand side of the assignment is your cpuif's name. This
     text is what the end-user uses in the command line interface to select your
     CPUIF implementation.
+*   ``my_package.my_module:MyCPUIF``: This is the import path that
+    points to your CPUIF class definition.
diff --git a/src/peakrdl_regblock/validate_design.py b/src/peakrdl_regblock/validate_design.py
index 1ce14f2..a32bc05 100644
--- a/src/peakrdl_regblock/validate_design.py
+++ b/src/peakrdl_regblock/validate_design.py
@@ -23,7 +23,6 @@ class DesignValidator(RDLListener):
         self.msg = self.top_node.env.msg
 
         self._contains_external_block_stack = [] # type: List[bool]
-        self.contains_external_block = False
 
     @property
     def top_node(self) -> 'AddrmapNode':
@@ -178,9 +177,6 @@ class DesignValidator(RDLListener):
             if self._contains_external_block_stack:
                 # Still in the design. Update stack
                 self._contains_external_block_stack[-1] |= contains_external_block
-            else:
-                # Exiting top addrmap. Resolve final answer
-                self.contains_external_block = contains_external_block
 
             if contains_external_block:
                 # Check that addressing follows strict alignment rules to allow
diff --git a/tests/README.md b/tests/README.md
index bb3996c..c20ca4e 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -48,13 +48,14 @@ Use `pytest --workers auto` to run tests in parallel.
 
 To run all tests:
 ```bash
-python3 setup.py install
-pytest tests
+python3 -m pip install ".[cli]"
+cd tests
+pytest
 ```
 
 You can also run a specific testcase. For example:
 ```bash
-pytest tests/test_hw_access
+pytest test_hw_access
 ```
 
 Command-line arguments can be used to explicitly select which simulator/synthesis tools are used