diff --git a/esphome/arduino8266/framework.py b/esphome/arduino8266/framework.py
index a574313f49..5ca305e0ef 100644
--- a/esphome/arduino8266/framework.py
+++ b/esphome/arduino8266/framework.py
@@ -142,8 +142,9 @@ def check_and_install(framework_version: Version) -> InstalledPaths:
 
 
 # Sentinel: "resolve for me" (None is a real value meaning disabled).
-# run_compile resolves once and threads the result so one build never pays
-# the PATH scan and runnability probe three times.
+# The native run_compile (a later PR in the chain) will resolve once and
+# thread the result so one build never pays the PATH scan and runnability
+# probe three times.
 CCACHE_UNRESOLVED: Any = object()
 
 
diff --git a/tests/unit_tests/test_arduino8266_framework.py b/tests/unit_tests/test_arduino8266_framework.py
index cd79c57f8f..c173fb27f2 100644
--- a/tests/unit_tests/test_arduino8266_framework.py
+++ b/tests/unit_tests/test_arduino8266_framework.py
@@ -157,7 +157,10 @@ def test_get_build_env_without_path_has_no_empty_entry(tmp_path: Path) -> None:
 def test_ccache_env_accepts_a_preresolved_path() -> None:
     """A caller that already resolved ccache threads it through; the probe
     must not run again (None means resolved-and-disabled)."""
-    with patch.object(framework, "ccache_path") as mock_resolve:
+    with (
+        patch.dict(os.environ, {}, clear=True),
+        patch.object(framework, "ccache_path") as mock_resolve,
+    ):
         assert framework.ccache_env(None) == {}
         env = framework.ccache_env("/usr/bin/ccache")
     mock_resolve.assert_not_called()