diff --git a/src/peakrdl_regblock/read_buffering/storage_generator.py b/src/peakrdl_regblock/read_buffering/storage_generator.py
index e6eba18..4f291bc 100644
--- a/src/peakrdl_regblock/read_buffering/storage_generator.py
+++ b/src/peakrdl_regblock/read_buffering/storage_generator.py
@@ -1,8 +1,13 @@
-from systemrdl.node import FieldNode, RegNode
+from systemrdl.node import FieldNode, RegNode, AddressableNode
+from systemrdl.walker import WalkerAction
 
 from ..struct_generator import RDLStructGenerator
 
 class RBufStorageStructGenerator(RDLStructGenerator):
+    def enter_AddressableComponent(self, node: AddressableNode) -> WalkerAction:
+        if node.external :
+            return WalkerAction.SkipDescendants
+        return WalkerAction.Continue
 
     def enter_Field(self, node: FieldNode) -> None:
         # suppress parent class's field behavior
diff --git a/src/peakrdl_regblock/write_buffering/storage_generator.py b/src/peakrdl_regblock/write_buffering/storage_generator.py
index 3cae471..b6322b7 100644
--- a/src/peakrdl_regblock/write_buffering/storage_generator.py
+++ b/src/peakrdl_regblock/write_buffering/storage_generator.py
@@ -1,6 +1,7 @@
 from typing import TYPE_CHECKING
 
-from systemrdl.node import FieldNode, RegNode
+from systemrdl.node import FieldNode, RegNode, AddressableNode
+from systemrdl.walker import WalkerAction
 
 from ..struct_generator import RDLStructGenerator
 
@@ -12,6 +13,11 @@ class WBufStorageStructGenerator(RDLStructGenerator):
         super().__init__()
         self.wbuf = wbuf
 
+    def enter_AddressableComponent(self, node: AddressableNode) -> WalkerAction:
+        if node.external :
+            return WalkerAction.SkipDescendants
+        return WalkerAction.Continue
+
     def enter_Field(self, node: FieldNode) -> None:
         # suppress parent class's field behavior
         pass
diff --git a/tests/test_validation_errors/testcase.py b/tests/test_validation_errors/testcase.py
index 3267dac..1ddd728 100644
--- a/tests/test_validation_errors/testcase.py
+++ b/tests/test_validation_errors/testcase.py
@@ -10,10 +10,6 @@ class TestValidationErrors(BaseTestCase):
         # Stub usual pre-test setup
         pass
 
-    def tearDown(self):
-        # Delete any cruft that may get generated
-        self.delete_run_dir()
-
     def assert_validate_error(self, rdl_file: str, err_regex: str) -> None:
         self.rdl_file = rdl_file
         f = io.StringIO()