diff --git a/Makefile b/Makefile
index 75347da..57f65d5 100644
--- a/Makefile
+++ b/Makefile
@@ -55,4 +55,4 @@ __ext__/System_MIDIRemoteScripts/.make.decompile: $(SYSTEM_MIDI_REMOTE_SCRIPTS_D
 .make.install: pyproject.toml poetry.lock
 	@if [ -z $(POETRY) ]; then echo "Poetry could not be found. See https://python-poetry.org/docs/"; exit 2; fi
 	$(POETRY) install
-	touch $@
\ No newline at end of file
+	touch $@
diff --git a/control_surface/configuration.py b/control_surface/configuration.py
index 5f21502..680a4a4 100644
--- a/control_surface/configuration.py
+++ b/control_surface/configuration.py
@@ -294,19 +294,22 @@ def override_nav(
 
 
 def _override_elements_with_nav(
+    # Names of elements representing each direction.
     left: str,
     right: str,
     up: str,
     down: str,
+    # Nav to apply in the horizontal/vertical directions, or None if no nav should be specified.
     horizontal: Optional[NavigationTarget],
     vertical: Optional[NavigationTarget],
 ) -> List[ElementOverride]:
     results: List[ElementOverride] = []
-    for down_element, up_element, target in (
+    elements_and_targets: Iterable[Tuple[str, str, Optional[NavigationTarget]]] = (
         (left, right, horizontal),
         # The down button increases values - think selected scene.
         (up, down, vertical),
-    ):
+    )
+    for down_element, up_element, target in elements_and_targets:
         # Get a unique control name based on an element name.
         def background_control_name(element: str):
             return element.replace("[", "_").replace("]", "_")
diff --git a/control_surface/mappings.py b/control_surface/mappings.py
index 005ad70..a65efdd 100644
--- a/control_surface/mappings.py
+++ b/control_surface/mappings.py
@@ -456,12 +456,13 @@ def _navigation_mode(
         vertical_target: Optional[NavigationTarget],
     ) -> List[SimpleModeSpecification]:
         component_mappings: Dict[str, Dict[str, str]] = {}
-        for navigation_target, down_button, up_button in (
+        targets_and_elements: Iterable[Tuple[Optional[NavigationTarget], str, str]] = (
             (horizontal_target, "nav_left_button", "nav_right_button"),
             # The down button generally increases values, e.g. the selected scene index,
             # session ring position...
             (vertical_target, "nav_up_button", "nav_down_button"),
-        ):
+        )
+        for navigation_target, down_button, up_button in targets_and_elements:
             if navigation_target:
                 component, down_attribute, up_attribute = NAVIGATION_TARGET_MAPPINGS[
                     navigation_target